For almost two decades, CVE has been considered an industry standard for vulnerability tracking. A CVE ID can be affiliated with many vulnerabilities, in a format like CVE-2014-54321. Note my choice in ID, from 2014 with a consecutive set of numbers. That is because I specifically chose a ‘sample’ CVE that was set aside as an example of the CVE ID Syntax Change in 2014. This change occurred when it was determined that 9,999 IDs for a single year was not going to be sufficient. Technical guidance on this is available, as well as more basic information and the announcement about the change. Starting out with this hopefully demonstrates that there may be more to an ID than meets the eye.
Fundamentally, the ID is simple; you have the CVE prefix, followed by a year identifier, and a numeric identifier. In the CVE used above, it would represent ID 54321 with a 2014 year identifier. Fairly simple! But you are reading an entire blog on these IDs by me so the spoiler is here. It isn’t so simple unfortunately. I want to give a rundown of what a CVE ID really is, and set the record straight. Why? Because I don’t think MITRE has done a good job with that, and worse, actively works against what could be a clear and simple policy. We’ll use CVE-YEAR-12345 as a representative example for the purpose of discussing these IDs to be clear about which part of an ID we’re talking about.
When CVE was started in 1999, assignments were made based on a public disclosure. However, from the beginning, the YEAR portion almost immediately was not guaranteed to represent the year of disclosure. This was because MITRE’s policy was to assign an ID for a pre-1999 vulnerability using a CVE-1999 ID. We can see this with CVE-1999-0145 which was assigned for the infamous Sendmail WIZ command, allowing remote root access. This feature was publicly disclosed as a vulnerability on November 26, 1983 as best I have determined (the Sendmail changelog). While it was a known vulnerability and used before that, it was privately shared. If there is a public reference to this vulnerability before that date, leave a comment please!
The takeaway is that a vulnerability from 1983 has a CVE-1999 identifier. So from the very first year, MITRE set a clear precedent that the YEAR portion of an ID does not represent the year of discovery or disclosure. You may think this only happened for vulnerabilities prior to 1999, but that isn’t the case. In the big picture, meaning the 22 years of CVE running, an ID typically does represent the disclosure year. However, per one of CVE’s founders, “because of CVE reservation, sometimes it aligned with year of discovery“. That is entirely logical and expected as a CVE ID could be used to track a vulnerability internally at a company before it was disclosed. For example, BigVendor could use the CVE ID not only for their internal teams, such as communicating between security and engineering, but when discussing a vulnerability with the researcher. If a researcher reported several vulnerabilities, using an ID to refer to one of them was much easier than the file/function/vector.
For the early CVE Numbering Authorities (CNA), companies that were authorized to assign a CVE without going through MITRE, this was a common side effect of assigning. If a researcher discovered a vulnerability on December 25 and immediately reported it to the vendor, it may be given e.g. a CVE-2020 ID. When the vendor fixed the vulnerability and the disclosure was coordinated, that might happen in 2021. The founder of CVE I spoke to told me there “weren’t any hard and fast rules for CNAs” even at the start. So one CNA might assign upon learning of the vulnerability while another might assign on public disclosure.
Not convinced for some reason? Let’s check the CVE FAQ about “year portion of a CVE ID”!
What is the significance and meaning of the YEAR portion of a CVE ID CVE IDs have the format CVE-YYYY-NNNNN. The YYYY portion is the year that the CVE ID was assigned OR the year the vulnerability was made public (if before the CVE ID was assigned).
The year portion is not used to indicate when the vulnerability was discovered, but only when it was made public or assigned.
A vulnerability is discovered in 2016, and a CVE ID is requested for that vulnerability in 2016. The CVE ID would be of the form “CVE-2016-NNNN”. A vulnerability is discovered in 2015 and made public in 2016. If the CVE ID is requested in 2016, the CVE ID would be of the form “CVE-2016-NNNNN”.
All clear, no doubts, case closed!
That clear policy is conflicting or may introduce confusion in places. Looking at MITRE’s page on CVE Identifiers, we see that the “The process of creating a CVE Record begins with the discovery of a potential cybersecurity vulnerability.” My emphasis on ‘discovery’ as that means the ID would reflect when it was discovered, and not necessarily even when it was reported to the vendor. There are many cases where a researcher finds a vulnerability but may wait days, weeks, months, or even years before reporting it to the vendor for different reasons. So it is more applicable that the ID will be assigned based on when the vendor learns of the vulnerability in cases of coordinated disclosure with a CNA. Otherwise, a bulk of CVEs are assigned based on the disclosure year.
It gets messier. At the beginning of each year, each CNA will get a pool of CVE IDs assigned. The size of the pool varies by CNA and is roughly based on the prior year of assignments. A CNA that disclosed 10 vulnerabilities in the prior year is likely to get 10 – 15 IDs the subsequent year. Per section 5.1.4 of the CNA rules, any IDs that are not used in a calendar year should be REJECTed if they were not assigned to an issue. “Those CVE IDs that were unused would be rejected.” But then, it stipulates that the CNA can get “CVE IDs for previous calendar years can always be requested if necessary.” So per current rules, a CNA can request a new ID from a prior year despite REJECTing IDs that were previously included in their pool. That means it is entirely optional, up to each CNA, on how they assign.
[Update: Note that the pool of IDs a CNA gets one year may not be the same the next. Not only in regards to the size of the pool, but the first ID may be in an entirely different range. e.g. 2019-1000 vs 2020-8000.]
The take-away from all this is that we now have many reasons why a CVE ID YEAR component does not necessarily tie to when it was disclosed. The more important take-away? If you are generating statistics based on the YEAR component, you are doing it wrong. Any statistics you generate are immediately inaccurate and cannot be trusted. So please don’t do it!
Finally, a brief overview of the numeric string used after the YEAR. Going back to our example, CVE-YEAR-12345, it is easy to start to make assumptions about 12345. The most prevalent assumption, and completely incorrect, is that IDs are issued in a sequential order. This is not true! Covered above, CNAs are given pools of IDs at the beginning of each year. Oracle and IBM assign over 700 vulnerabilities a year, so the pool of IDs they receive is substantial. There are over 160 participating CNAs currently, and if each only received 100 IDs, that is over 16,000 IDs that are assigned before January 1st.
In 2021, the effect of this can be seen very clearly. Halfway through April and we’re already seeing public IDs in the 30k range. For example, CVE-2021-30030 is open and represents a vulnerability first disclosed on March 28th. According to VulnDB, there are only 7,074 total vulnerabilities disclosed this year so far. That means we can clearly see that CVE IDs are not assigned in order.
[Stupid WordPress. This was scheduled to publish Nov 23 but didn’t for some reason. Here it is, a bit late…]
On Friday, Maddie Stone from the Google P0 team Tweeted about the 0-day exploits her team tracks. As someone who checks that sheet weekly and tracks vulnerabilities, including ones ‘discovered in the wild’, this is a topic that is squarely in my tiny niche in the industry. Also, big fan of the P0 team!
I replied to her Tweet suggesting it come with a disclaimer that it didn’t represent “all” 0-days, rather they tracked high-end 0-day used primarily in “APT” attacks. Ben Hawkes, manager of the team, replied and agreed with that assessment. Before we proceed, let’s define 0-day real quick since the term is used for a variety of vulnerabilities, often incorrectly.
In this case, the context is a 0-day is a vulnerability that was actually found being exploited in the wild before there was public knowledge of it. In Risk Based Security’s VulnDB, we track that as “discovered in the wild“. Since VulnDB is comprehensive and our goal is to track every vulnerability, regardless of software or severity, we tend to aggregate a lot more than others. As of this post, we have over 78,000 vulnerabilities that aren’t found in CVE / NVD as a point of comparison. In my reply to Maddie I pointed out that we had seen 51 this year compared to their 22.
Next, Allen Householder replied to me asking a fun point, which is how many vulnerabilities did that really represent. Out of the 20,000+ vulnerabilities aggregated in 2020, we have 51 that are flagged as “discovered in the wild”. That represents only 0.25% of all vulnerabilities this year. One point I made previously is that Google’s team likely doesn’t care about a 0-day in the “Adning Advertising Plugin for WordPress” despite it being used to compromise WordPress blogs.
So with that number in mind, it goes back to the narrative that companies need to be scared of 0-days. They absolutely do! But… and this is the big qualifier that needs to come with that fear, is that perhaps they don’t need to be as afraid of 0-days as they do of already public vulnerabilities that they missed. With only 51 0-days in 2020, that means a vast majority of organizations simply aren’t likely to be targeted. Fully patching all known vulnerabilities that impact them should be priority one.
More to the point, vulnerabilities that have functional public exploits allowing anyone to trivially launch a viable attack are consistently a much bigger risk than the elusive 0-days. That is also one reminder of how often times CVSS falls short, if your vulnerability intelligence doesn’t provide Temporal scoring or exploit availability. Organizations making risk decisions only using the CVSS Base score are missing out on an important risk attribute.
I’ll end this blog with some arbitrary statistics around 0-days for fun! These are based on VulnDB data as of 11/21/2020. Note that metadata is less complete before 2012, which includes ‘discovered in the wild’ classification.
241,690 vulnerabilities, only 641 are 0days (0.27%)
14 are in Google products: Chrome (5), V8 (3), Android (6)
146 are in Microsoft products: Windows (63), IE (36)
13 are in Apple products
7 are in Oracle products: Java (4)
62 are in Adobe products: Flash (38), Reader (14)
18 are in security products 😞
The oldest is from 1975 in RSTS/E! Yes, for real.
The oldest you likely recognize is Sendmail in November, 1983
At the end of each year, we see articles covering how many vulnerabilities were disclosed the prior year. Because the articles are written about the same time of year, it gives a fairly good initial comparison from year to year; at least, on the surface. This is the foundation of statements such as “Security vulnerabilities in critical infrastructure up 600%”. My company, Risk Based Security, even includes that general type of observation in our vulnerability reports, with caveats. These sensationalized counts and figures are also often used to make claims that one product is more or less secure than another, when the vulnerability counts cannot typically be used for such claims as they are built on severely incomplete data. In reality, we must remember that such numbers are only a snapshot in time and serve as a quick comparison between years, not much more.
Before we get to the “moving target” topic, we need to cover a bit of background on how all this happens.
First, consider that even with a large team doing vulnerability aggregation, there is a limit to the number of sources that can be monitored. While a team might monitor over 4,000 sources on a daily to weekly basis, we know there are a lot more out there. As new researchers create their blogs, older vendors finally create advisory pages, and new vendors pop up, the new sources are growing at an incredible rate. Additionally, consider that there are over a million results for “site:github.com changelog.md” (not to mention variations like “release_notes” or “changelog.txt” and similar) that could potentially host a trove of vague vulnerability mentions. Even more daunting, back in 2010 GitHub was hosting 1 million repositories and now they are over 100 million. That means there are an overwhelming number of bug trackers, pull requests, and over a billion commits on a single site. Any company that claims to monitor all of that or “millions” or sources? Do your due diligence and be ready to walk away from them.
Second, due to available resources, vulnerability aggregation teams have to prioritize their activity. This is usually done by vendor, product, and the time frame where higher deployment vendors and products get the most attention. With “time frame”, emphasis is placed on the more recent vulnerabilities as they are most likely to be relevant to organizations. Moving past that, a vulnerability intelligence (VI) provider must be working with clients to learn what resources they use in their organization, as it allows them to prioritize and ensure that they are covering exactly what is deployed first and foremost. After all that, as time permits, they have to come up with new ways to expand source coverage without compromising quality or speed.
With that in mind, consider a vendor that finally publishes a changelog or makes their bug tracker open for everyone. While a VI team should love to go through such resources as far back as possible, they have to limit themselves to vulnerabilities for the current year, and then some amount of time farther back in case clients are using older versions (especially for third-party dependencies). Time permitting, the team should then go back even further to dig for older and more obscure vulnerabilities. While these may or may not immediately benefit clients based on the software they are running, it does contribute directly to the vulnerability history of a given product or vendor. This is invaluable in determining the “cost of ownership” for a product and is vital to making a decision between multiple vendors offering the same type of solutions. With all of that data, it is trivial for a VI provider to provide a quick and easy-to-understand picture of that cost.
Even with very limited time to dig that far back into sources, the impact can still be seen clearly. In January of 2013, Risk Based Security’s VulnDB team had aggregated 8,822 vulnerabilities for the 2012 calendar year, and CVE covered only 4,765 of them (54%). Compared to the prior year (7,911 in 2011), we could say that disclosures increased around 10%. The next question we must ask is if those numbers aged well and hold true today.
Looking at VulnDB now, there were 10,856 vulnerabilities disclosed in 2012. So in the past eight years, the team has managed to find an additional 2,034 vulnerabilities disclosed that year. That means comparing 2012’s updated 10,856 count with the older 7,911 count for 2011, the percent increase was closer to 28%. But wait, we can no longer use the 7,911 count for 2011 either, since that too is a moving target! Ultimately, as previously stated, these disclosure numbers are only good as a snapshot in time. Depending when you perform the count, you may find wildly varying results that could heavily bias any conclusions you try to make. Do the people writing the statistics you read and cite disclaim that?
In January of 2013, I started taking counts every month for how many vulnerabilities VulnDB aggregated for the 2012 calendar year. Almost eight years later, and this blog and chart shows just how much that number can change. As with all vulnerability statistics, please make sure you fully understand what they really mean and disclaim as needed!
With this visual we can see that in the years after 2012, vulnerability aggregation continued to rise considerably. Over time that growth tapers off as the team simply didn’t have time to keep digging that far back into changelogs and bug trackers looking for more vulnerabilities that were less beneficial to organizations.
The tl;dr takeaways:
The number of vulnerabilities disclosed in a given year is static, but the VI teams that aggregate the information won’t find them all that year.
Vulnerabilities by year, as reported, will slowly climb over time as additional aggregation work is performed.
While that newly aggregated data may be “old” as far as what software is being used within an organization, it still contributes to better metadata and product/vendor evaluation (“cost of ownership”)
[This was originally published on the OSVDB blog.]
The notion of expertise in any field is fascinating. It crosses so many aspects of humans and our perception. For example, two people in the same discipline, each with the highest honors academic can grant, can still have very different expertise within that field. Society and science have advanced so we don’t have just have “science” experts and medical doctors can specialize to extreme degrees. Within Information Security, we see the same where there are experts in penetration testing, malware analysis, reverse engineering, security administration, and more.
In the context of a software company, especially one that does not specifically specialize in security (and is trivial to argue was late to the security game), you cannot shoehorn them into any specific discipline or expertise. We can all absolutely agree there is an absolute incredible level of expertise across a variety of disciplines within Microsoft. So when Microsoft releases yet another report that speaks to vulnerability disclosures, the only thing I can think of is duality. Especially in the context of a report that puts forth some expertise that they are uniquely qualified to speak on, while mixed with a topic that pre-dates Microsoft and they certainly aren’t qualified to speak on to some degree.
A Tweet from Carsten Eiram pointed me to the latest report, and brought up the obvious fact that it seemed to be way off when it comes to vulnerability disclosures.
The “MS SIR” he refers to is the Microsoft Security Intelligence Report, Volume 21 which covers “January through June, 2016” (direct PDF download).
It’s always amusing to me that you get legal disclaimers in such analysis papers before you even get a summary of the paper:
Basically, the take away is that they don’t stand behind their data. Honestly, the fact I am blogging about this suggests that is a good move and that they should not. The next thing that is fascinating is that it was written by 33 authors and 14 contributors. Since you don’t know which of them worked on the vulnerability section, it means we get to hold them all accountable. Either they can break it down by author and section, or they all signed off on the entire paper. Sorry, the joys of academic papers!
After the legal disclaimers, then you start to get the analysis disclaimers, which are more telling to me. Companies love to blindly throw legal disclaimers on anything and everything (e.g. I bet you still get legal disclaimers in the footer of emails you receive, that have no merit). When they start to explain their results via disclaimers while not actually including their methodology, anyone reading the report should be concerned. From their “About this report” section:
This volume of the Microsoft Security Intelligence Report focuses on the first and second quarters of 2016, with trend data for the last several quarters presented on a quarterly basis. Because vulnerability disclosures can be highly inconsistent from quarter to quarter and often occur disproportionately at certain times of the year, statistics about vulnerability disclosures are presented on a half-yearly basis.
This is a fairly specific statement that speaks as if it is fact that vulnerability trends vary by quarter (they do!), but potentially ignores the fact that they can also vary by half-year or year. We have seen that impact not only a year, but the comparison to every year prior (e.g. Will Dormann in 2014 and his Tapioca project). Arbitrarily saying that it is a ‘quarter’ or ‘half-year’ does not demonstrate experience in aggregating vulnerabilities, instead it is a rather arbitrary and short time-frame. Focusing on a quarter can easily ignore some of the biases that impact vulnerability aggregation as outlined by Steve Christey and my talk titled “Buying Into the Bias: Why Vulnerability Statistics Suck” (PPT).
Jumping down to the “Ten years of exploits: A long-term study of exploitation of vulnerabilities in Microsoft software” section, Microsoft states:
However, despite the increasing number of disclosures, the number of remote code execution (RCE) and elevation of privilege (EOP) vulnerabilities in Microsoft software has declined significantly.
Doing a title search of Risk Based Security’s VulnDB for “microsoft windows local privilege escalation” tells a potentially different story. While 2015 is technically lower than 2011 and 2013, it is significantly higher than 2012 and 2014. I can’t say for certain why these dips occur, but they are very interesting.
Thousands of vulnerabilities are publicly disclosed across the industry every year. The 4,512 vulnerabilities disclosed during the second half of 2014 (2H14) is the largest number of vulnerabilities disclosed in any half-year period since the Common Vulnerabilities and Exposures system was launched in 1999.
This quote from the report explicitly shows serious bias in their source data, and further shows that they do not consider their wording. This would be a bit more accurate saying “The 4,512 vulnerabilities aggregated by MITRE during the second half of 2014…” The simple fact is, a lot more than 4,512 vulnerabilities were disclosed during that time. VulnDB shows that they aggregated 8,836 vulnerabilities in that same period, but less than the 9,016 vulnerabilities aggregated in the second half of 2015. Microsoft also doesn’t disclaim that the second half of 2014 is when the aforementioned Will Dormann released the results of his ‘Tapioca’ project totaling over 20,500 vulnerabilities, only 1,384 of which received CVE IDs. Why? Because CVE basically said “it isn’t worth it”, and they weren’t the only vulnerability database to do so. With all of this in mind, Microsoft’s comment about the second half of 2014 becomes a lot more complicated.
The information in this section is compiled from vulnerability disclosure data that is published in the National Vulnerability Database (NVD), the US government’s repository of standards-based vulnerability management data at nvd.nist.gov. The NVD represents all disclosures that have a published CVE (Common Vulnerabilities and Exposures) identifier.
This is a curious statement, since CVE is run by MITRE under a contract from the Department of Homeland Security (DHS), making it a “US government repository” too. More importantly, NVD is essentially a clone of CVE that just wraps additional meta-data around each entry (e.g. CPE, CWE, and CVSS scoring). This also reminds us that they opted to use a limited data set, one that is well known in the Information Security field as being woefully incomplete. So even a company as large as Microsoft, with expected expertise in vulnerabilities, opts to use a sub-par data set which drastically influences statistics.
Figure 23. Remote code executable (RCE) and elevation of privilege (EOP) vulnerability disclosures in Microsoft software known to be exploited before the corresponding security update release or within 30 days afterward, 2006–2015
The explanation for Figure 23 is problematic in several ways. Does it cherry pick RCE and EOP while ignoring context-dependent (aka user-assisted) issues? Or does this represent all Microsoft vulnerabilities? This is important to ask as most web browser exploits are considered to be context-dependent and coveted by the bad guys. This could be Microsoft conveniently leaving out a subset of vulnerabilities that would make the stats look worse. Next, looking at 2015 as an example from their chart, they say 18 vulnerabilities were exploited and 397 were not. Of the 560 Microsoft vulnerabilities aggregated by VulnDB in 2015, 48 have a known public exploit. Rather than check each one to determine the time from disclosure to exploit publication, I’ll ask a more important question. What is the provenance of Microsoft’s exploitation data? That isn’t something CVE or NVD track.
Figure 25 illustrates the number of vulnerability disclosures across the software industry for each half-year period since 2H13
Once again, Microsoft fails to use the correct wording. This is not the number of vulnerability disclosures, this is the number of disclosures aggregated by MITRE/CVE. Here is their chart from the report:
Under the chart they claim:
Vulnerability disclosures across the industry decreased 9.8 percent between 2H15 and 1H16, to just above 3,000.
As mentioned earlier, since Microsoft is using a sub-par data set, I feel it is important to see what this chart would look like using more complete data. More importantly, watch how it invalidates their claim about an industry decrease of 9.8 percent between 2H15 and 1H16, since RBS shows the drop is closer to 18%.
I have blogged about vulnerability statistics, focusing on these types of reports, for quite a while now. And yet, every year we see the exact same mistakes made by just about every company publishing statistics on vulnerabilities. Remember, unless they are aggregating vulnerabilities every day, they are losing a serious understanding of the data they work with.
March 19, 2017 Update – Carsten Eiram (@carsteneiram) pointed out that the pattern of local privilege escalation numbers actually follow an expected pattern with knowledge of researcher activity and trends:
In 2011, Tarjei Mandt while he was at Norman found a metric ton of LPEs in win32k.sys as part of a project.
In 2013, it was Mateusz Jurczyk’s turn to also hit win32k.sys by focusing on a bug-class he dubbed “double-fetch” (he’s currently starting that project up again to see if he with tweaks can find more vulns).
And in 2015, Nils Sommer (reported via Google P0) was hitting win32k.sys again along with a few other drivers and churned out a respectable amount of LPE vulnerabilities.
So 2012 and 2014 represent “standard” years while 2011, 2013, and 2015 had specific high-profile researchers focus on Windows LPE flaws via various fuzzing projects.
So the explanation is the same explanation we almost always see: vulnerability disclosures and statistics are so incredibly researcher driven based on which product / component / vulnerability type a researcher or group of researchers decides to focus on.
In addition to my comments, Roytman had a long call with Adrian Sanabria which led to generating a new set of data with a different scope. From the Kenna blog:
We had an excellent offline discussion in which he dove deeply into the assumptions of my work, asked thoughtful, deep questions in private, and together, we came up with a better metric for generating a top 10 vulnerabilities list. To address these issues, I scaled the total successful exploitation count for every vulnerability in 2015 by the number of observed occurrences of that vulnerability in Kenna’s aggregate dataset. Sifting through 265 million vulnerabilities gives us a top 10 list perhaps more in line with what was expected – but equally unexpected! The takeaway here is that datasets like the one explored in the DBIR might be noisy, might have false positives and the like, but carefully applied to your enterprise the additional context successful exploitation data lends to vulnerability management is priceless.
I won’t go into much detail in this blog, but will say that I disagree with the statement that severely flawed data can produce takeaways that are “priceless”. Organizations acting on these top 10 lists may be spending time and resources chasing vulnerabilities that do not impact them, or pose very little risk compared to other threats they face. That action most certainly has a price; one that can be enumerated to some degree due to the cost of the employee time required. With that in mind, let’s look at the methodology which is spelled out in more detail than the DBIR, before we consider the new top 10 list Roytman generated. First, his notes on the data examined:
The first is a convenience sample that includes 2,442,792 assets (defined as: workstations, servers, databases, ips, mobile devices, etc) and 264,912,235 vulnerabilities associated to those assets. The vulnerabilities are generated by 8 different scanners, they are: Beyond Security, Tripwire, McAfee VM, Qualys, Tenable, BeyondTrust, Rapid7, and OpenVAS . This dataset is used in determining remediation rates and the normalized open rate of vulnerabilities.
I am curious if it is normal practice to consider an IP address an asset, when the system that addresses the IP is largely considered the asset. Moving past that, one point that sticks in my mind is the tools that generate the data. From the list above, consider that Beyond Security claims to have “what is arguably the world’s most complete database of security vulnerabilities.” Click around their site and you see that “the AVDS database includes over 10,000 known vulnerabilities and the updates include discoveries by our own team and those discovered by corporate and private security teams around the world.” That is less than 25% of what CVE has, and less than 10% of what VulnDB has. They even show you that they only cover 200 CVE IDs for 2016, as compared to the 1,474 open 2016 CVEs.
The second is a convenience sample that includes 3,615,706,022 successful exploitation events which all take place in 2015 which come from Dell Secureworks’ Counter-Threat Unit and Alienvault’s Open Threat Exchange.
The third qualification, describing the methodology is perhaps the most important, and was lacking in the DBIR:
Please note the methodology of data collection: Successful Exploitation is defined as one successful technical exploitation of a vulnerability on one machine at a particular timestamp. The event is defined as: 1. An asset has a known CVE open. 2. An attack come in that matches the signature for that CVE on that asset and 3. One or more IOCs are detected/correlated post attack. It is not necessarily a loss of a data, or even root on a machine. It is just the successful use of whatever condition is outlined in a CVE.
I have reached out to Michael and requested a sampling of data for two of the CVE IDs on his new list, and he is going to do so. In the meantime, I had a discussion with several people more familiar with IDS than myself and asked about how they would detect attacks for CVE-2013-0229 and CVE-2001-0540 as an example. Sure, detecting a specific type of packet meant to trigger this is one thing, but what is the threshold for the IDS to say it is an attack, when exploitation requires “a large number of malformed Remote Desktop Protocol (RDP) requests“. Is there a specific number of packets for it to flag an attack in progress? If too low, it may be prone to a high number of false positives. If too high, it may not detect a successful exploitation of the issue. Which leads into the second part of the methodology, comparing it with “one or more IOCs [that] are detected/correlated post attack”. In this case, it would presumably be the targeted service not responding, which could be detected a number of ways (e.g. probing the port, seeing specific errors in the logs, noticing a given process not running). Once the service is down, is the IDS that isn’t aware of the host state still cataloging a single attack? Or is it generating alerts every X minutes it detects an attack ongoing? Hopefully the data Michael sends will help me better understand how that correlation is being made, as it represents a source of incredible bias for the resulting data analysis.
Moving on to Roytman’s new list using the above data and methodology, here is the top 10 list he sees in the data:
2015-03-05 – 2015-1637 – Microsoft Windows Secure Channel (Schannel) RSA Temporary Key Handling EXPORT_RSA Ciphers Downgrade MitM (FREAK)
2001-12-20 – 2001-0876 – Microsoft Windows Universal Plug and Play NOTIFY Directive URL Handling Remote Overflow
2001-12-20 – 2001-0877 – Microsoft Windows Universal Plug and Play NOTIFY Request Remote DoS
2001-07-25 – 2001-0540 – Microsoft Windows Terminal Server RDP Request Handling Memory Exhaustion Remote DoS
Roytman prefaces that list with a comment that the “top 10 list perhaps more in line with what was expected – but equally unexpected!” Indeed, that is certainly true. Expected? A high-profile vulnerability disclosed in 2014 that was seen being widely exploited then, and subsequent years, something sorely missing from the DBIR list even after the corrected CVE IDs were factored in. This is the type of vulnerability almost everyone expected to top the list due to how easy it was to exploit, and knowing that it had been used heavily. This speaks to the original point and reason for the first blog; all the data ‘science’ in the world that produces highly questionable results should not be taken as gospel. Even if the methodology was sound, it doesn’t mean the data being used was.
Unfortunately, Roytman’s revised list deviates quickly into the “equally unexpected“. The first DBIR report list had a single denial of service (DoS) attack on the list, which stood out as odd. The revised list bumped that number to two which was a bit odd. The most recent list expands that to six DoS attacks, which is highly questionable for one reason or another. First, you can question the data set and methodology leading to this conclusion, but let’s say that passes muster solely for the sake of argument. Second, you can question why so many denial of service attacks are on a top 10 most exploited vulnerabilities list, framed in a context that uses the word ‘compromise’, riding on the back of a report centered around data breaches. These attacks are not causing attackers to gain privileges or steal data. They are a nuisance most of the time, or potentially used in serious DoS attacks other times. It makes one question why DoS attacks weren’t dropped from the results completely, and disclaimed as such! Or, generate two lists; one with results based on raw data, DoS and everything, and a second list that focuses on vulnerabilities that may allow for privileges to be gained and a real compromise to happen.
I cannot stress this enough. Using a term like ‘Indicator of Compromise’ (IOC) in the context of DoS attacks is disingenuous and misleading. Going back to Roytman’s introduction into this section where he makes a comment about seeing the trees (referring to the classic metaphor), I find it ironic as that sums up the purpose of my blog. The DBIR was written as if they could only see the trees (data points), and not the forest (bigger picture), which is what many people took issue with.
One point that I overlooked on the original list, and still appears on the new list, is the presence of FREAK (twice even). Fortunately for me, Thomas Ptacek does a great job explaining why FREAK is likely on the list, but absolutely should not be. Using Roytman’s blog and data, he calculates that attackers would have spent $332,183,325 using Amazon EC2 to exploit FREAK. He continues by citing one of the researchers who discovered FREAK explaining one way that a high number of false positives are generated on that particular vulnerability. He goes on to drive the point home, quoting the researcher and commenting that it likely has not been exploited in the wild by an average attacker.
Roytman essentially dismisses all of this in his blog post while saying that I am correct, that “IDS alerts generate a ton of false positives, vulnerability scanners often don’t revisit signatures, CVE is not a complete list of vulnerability definitions. But those are just the trees, and we’ll get to them later.” Unfortunately, he doesn’t get to it later in a way that provides meaningful insight into the questions about the data and conclusions. Dan Guido wrote an excellent summary of why the DBIR vulnerability section has issues, and factors in Roytman’s latest blog, breaking it all down in a manner that highlights the flaws. Even with the revised list, it is still missing the US-CERT top 30 previously cited, the Microsoft data, and the recently disclosed ‘top PoC exploits distributed on social media‘. At some point, one would logically conclude these lists should have more overlap. One thing I would love to see from Verizon and Kenna is a detailed explanation of their methodology as it relates to detecting client-side exploits, that appear to be the defacto standard for infecting tens, maybe hundreds of thousands of hosts, every year to create botnets.
I want to look at this from one more perspective, because I think it beautifully highlights how vulnerability analysis is a moving target, but in this case for all the wrong reasons. While most vulnerability aggregators and analysts are constantly adapting to new variations of vulnerabilities, new sources of vulnerability information, and new players in the game with wildly different styles of disclosure, others that come along after the data is generated and do analysis frequently seem to lose perspective in my experience. I believe this is such a case and is best illustrated in what the DBIR top 10 looks like over three revisions in less than two weeks. Yes, I know Roytman’s list isn’t officially the DBIR list, but he generated the initial data and then opted to do a different form of analysis putting it forth as something that is more representative due to applying his analysis to a more limited dataset that he presumably trusts more (i.e. the Kenna aggregate dataset). One has to wonder if this was brought up to Verizon as a better way to approach the list, and if so, why was it rejected.
The following lists show the evolution of the CVEs that appear on the top 10, with strikeout denoting the typos between the original DBIR and Gabe’s clarification which is reflected in current downloads, underlining to show any denial of service attacks, and bold to show the new CVE IDs that appear with Roytman’s reworking.
In my mail to Roytman asking for a sample data set, I suggested that it would be interesting to see him generate a list using his methodology, but remove any DoS attack (six of his ten), so the top list only included exploits that could achieve remote privileges of some sort. He replied to me with:
… and again, awesome idea. One of those all-too-simple in retrospect, damnit why didn’t I think of it earlier things.
I found this interesting thinking back to his use of the forest and the trees metaphor.
This year’s vulnerability data was provided by Kenna Security (formerly Risk I/O), and Verizon “also utilized vulnerability scan data provided by Beyond Trust, Qualys and Tripwire in support of this section.” So the data isn’t from a single vendor, but at least four vendors, giving the impression that the data should be well-rounded, and have less questions than last year.
From the report:
Secondly, attackers automate certain weaponized vulnerabilities and spray and pray them across the internet, sometimes yielding incredible success. The distribution is very similar to last year, with the top 10 vulnerabilities accounting for 85% of successful exploit traffic. While being aware of and fixing these mega-vulns is a solid first step, don’t forget that the other 15% consists of over 900 CVEs, which are also being actively exploited in the wild.
This is not encouraging, as they have 10 vulnerabilities that account for an incredible amount of traffic, and the footnoted list of CVE IDs suggests the same problems as last year. And just like last year, the report does not explain the methodology for detecting the vulnerabilities, does not include details about the generation of the statistics, and provides a loose definition of what “successfully exploited” means. Without more detail it is impossible for others to reproduce their results, and extremely difficult to explain or disclaim them as a third party reading the report. Going to the Kenna Security page about this report doesn’t really yield much clarity, but does highlight another potential flaw in the methodology:
Kenna’s Chief Data Scientist Michael Roytman was the primary author of this year’s “Vulnerabilities” chapter, analyzing a correlated threat data set that spans 200M+ successful exploitations across 500+ common vulnerabilities and exposures from over 20,000 enterprises in more than 150 countries.
It’s subtle, but notice they went through a data set that spans exploitations across “500+ common vulnerabilities and exposures”, also known as CVE. If the data is only looking for CVEs, then there is an incredibly large bias at play from the start, since they are missing at least half of the disclosed vulnerabilities. More importantly, this becomes a game of fractions that the industry is keen to overlook at every opportunity:
CVE represents approximately half of the disclosed vulnerabilities.
Vulnerability scanners and IPS/IDS don’t have signatures for all CVE IDs, so they look for some fraction of CVE.
Detection signatures are often flawed, leading to false positives and false negatives, meaning they are actually detecting a fraction of the CVE IDs they intend to.
Another crucial factor in how this data is generated is in the detection of the exploits. Of the four companies contributing data, one was founded in 2009 (Risk I/O / Kenna) and another in 2006 (Beyond Trust, in the context of this discussion). That leaves Qualys (founded 1999) and Tripwire (founded 1997), who are likely the sources of the signatures that detected the vulnerabilities. For those around in the late 90s, the vulnerability landscape was very different than today, and security products based on signatures back then are in some ways considered rudimentary compared to today. Over time, most security products do not revisit older signatures to improve them unless they have to, often due to customer demand. Newly formed companies basically never go back and write signatures for vulnerabilities from 1999. So it stands to reason that the detection of these issues are based on Qualys and/or Tripwire’s detection capabilities, and the signatures detecting these vulnerabilities are likely outdated and not as well-constructed as compared to their more recent signatures.
That leads us to ask, how many vulnerabilities are these companies really looking for? Where did the detection signatures originate and how accurate are they? While the DBIR does disclaim that the data used is a sample, they also admit “bias undoubtedly exists”. However, they don’t warn the reader of these extremely limiting caveats that put the entire data set into a perspective clearly showing strong bias. This, combined with the lack of detailed methodology for how these vulnerabilities are detected and correlated to measure ‘success’, ultimately means this data has little value other than for inclusion in pedestrian reports on vulnerabilities.
With that in mind, I can only go by what information is available. We’ll start with the concise list of the top 10 CVE IDs these four vulnerability intelligence providers say are being exploited the most, and Verizon labels as “successfully exploited”:
2015-03-05 – CVE-2015-1637 – Microsoft Windows Secure Channel (Schannel) RSA Temporary Key Handling EXPORT_RSA Ciphers Downgrade MitM (FREAK)
2001-12-20 – CVE-2001-0876 – Microsoft Windows Universal Plug and Play NOTIFY Directive URL Handling Remote Overflow
2001-04-13 – CVE-2001-0680 – QVT/Net / Term FTP Server LIST Command Traversal Remote File Access
1999-11-22 – CVE-1999-1058 – Vermillion FTPD Long CWD Command Handling Remote Overflow DoS
This list should raise serious red flags for anyone passingly familiar with vulnerabilities. Not only do we have very odd ‘top 10’ lists from last year and this year, but there is little overlap between them. How does 2015 show a top 10 list exploiting eight vulnerabilities with CVE identifiers between 1999 and 2002, meaning they had been exploited so much as many as thirteen years later, only to see them all drop off the list this year, to be replaced by new 15+ year old vulnerabilities? In addition to this oddity, there are more considerations leading to my top 10 list of questions about their list:
How does a local vulnerability based on a symlink overwrite flaw (CVE-2012-1054) make it into a top 10 list of “85% of successful exploit traffic“?
How does a local vulnerability in Puppet rank #3 on this list, given the install base of Puppet as compared to Adobe or Java?
If they are detecting exploits on the wire, shouldn’t we see Java, Adobe Reader, and Adobe Flash somewhere on the list? The “Slow and steady—but how slow?” section even talks about time-to-exploit for Adobe.
How do you distinguish an FTP LIST command exploit from one vendor to another? (e.g. CVE-2005-2726, CVE-2002-0558, CVE-2001-0933, CVE-2001-0680) According to the one-liner methodology, this is done via pairing SIEM data, suggesting that BlackMoon and Vermillion are that popular today.
Or is there a problem in generating this data, which would be more easily attributed to loose signatures detecting FTP attacks regardless of vendor?
Figure 12 in the report, which is described as “Count of CVEs exploited in 2015 by CVE publication date” is a curious thing to include, as the CVE publication date is very distinct from the vulnerability disclosure date. While a large percentage of CVE publication dates are within seven days of disclosure, many are not (e.g. CVE-2015-8852 disclosed 2015-03-23 and CVE publication on 2016-04-26). Enough to make this chart questionable as far as the insight it provides. Taking the data as presented, are they really saying that only ~ 73 vulnerabilities with a 2015 ID were successfully exploited in 2015 across “millions of successful real-world exploitations“? Given that 40 vulnerabilities were discovered in the wild, 33 of which have 2015 CVE IDs, that means that only ~40 other 2015 vulnerabilities were successfully exploited? If that is the takeaway, how is the security industry unable to stop the increasing wave of data breaches, the same kinds that led to this report? Something doesn’t add up here.
While people are cheering about the DBIR disclaiming there is sample bias (and not really enumerating it), they ignore the measurement bias, don’t speak to publication bias, don’t explain the attrition bias between 2015 and 2016, or potential chaining bias. As usual, the media is happy to glom onto such reports without asking any of these questions or providing critical analysis. As an industry, we need to keep challenging metrics and statistics to ensure they are not only accurate, but provide meaning that benefits us.
I hate to harp on simple transposition style mistakes in a report, but given the severity behind using numeric identifiers for vulnerabilities, it seems like that should have been double and triple-checked. Even then, I don’t understand how someone familiar with vulnerabilities could see either list and not ask many of the same questions I did, or provide more information in the report to back the claims. That said, let’s look at Gabe’s new list of CVEs. Bold and links are used to highlight the new ones:
2015-03-05 – 2015-1637 – Microsoft Windows Secure Channel (Schannel) RSA Temporary Key Handling EXPORT_RSA Ciphers Downgrade MitM (FREAK)
2001-12-20 – 2001-0877 – Microsoft Windows Universal Plug and Play NOTIFY Request Remote DoS
2001-12-20 – 2001-0876 – Microsoft Windows Universal Plug and Play NOTIFY Directive URL Handling Remote Overflow
2001-04-13 – 2001-0680 – QVT/Net / Term FTP Server LIST Command Traversal Remote File Access
1999-11-22 – 1999-1058 – Vermillion FTPD Long CWD Command Handling Remote Overflow DoS
The list gained another FTP server issue that doesn’t necessarily lead to privileges, and another remote denial of service attack, while losing the Puppet symlink (CVE-2012-1054) and the vague Oracle Enterprise Manager issue (CVE-2011-0877). All said and done, the list is just as confusing as before, perhaps more so. That gives us four FTP vulnerabilities, only one of which leads to remote code execution, and two denial of service attacks, that gain no real privileges for an attacker. As Andreas Lindh points out, that I failed to highlight, having a man-in-the-middle vulnerability occupy two spots on this list is also baffling in the context of the volume of attacks stated. Also note that with the addition of CVE-2002-1054 (Pablo FTP), there are now two vulnerabilities that appear on the DBIR 2015 and DBIR 2016 top ten CVE list.
Hopefully the forthcoming blog from Michael Roytman will shed some light on these issues.
It’s that time of year again! Vulnerability databases whip up reports touting statistics and observations based on their last year of collecting data. It’s understandable, especially for a commercial database, to show why your data source is the best. In the past, we haven’t had a strong desire to whip up a flashy PDF with our take on vulnerability disclosure statistics. Instead, we’ve focused more on educating others on why their statistics are often so horribly wrong or misleading. It should come as no surprise then, as we find ourselves forced to point out the errors in Secunia’s ways. We did the same thing last year in a long blog, giving more perspective and our own numbers for balance.
After reading this year’s report from Secunia, we could basically use last year’s blog as a template and just plug in new numbers. Instead, it is important to point out that after last year’s review, Secunia opted not to revise their methodology. Worse, they did not take any pointers from a presentation on vulnerability statistics Steve Christey (CVE / MITRE) and I did at BlackHat before last year’s report, pointing out the most common flaws in statistics and where the bias comes from. It is easy to chalk up last year’s report as being naive and not fully appreciating or understanding such statistics. This year though, they have no excuse. The numbers they report seem purposefully misleading and are a disservice to their customers and the community.
The headline of their press release and crux of their report is that they identified 15,435 vulnerabilities in 2014. This is entirely inaccurate, and completely misleading. This is fundamentally due to the same very flawed methodology they used last year, where they count a single vulnerability as many as 210 times (e.g. this year CVE-2014-0160, aka Heartbleed). Then factor in all of the other high profile “logo” vulnerabilities (e.g. FREAK, ShellShock), especially in OpenSSL, and the same handful of vulnerabilities will get counted hundreds or even a thousand times. To be abundantly clear, a vulnerability in a third-party library such as OpenSSL is one vulnerability. It doesn’t matter how many other products use and integrate that code, the fundamental flaw is in the library. Counting each product that implements OpenSSL as a distinct vulnerability, rather than a distinct occurrence of a vulnerability, is wrong. Worse, it actually highlights just how poor their statistics are, if you do accept their flawed methodology, as it is heavily used among thousands of applications that Secunia doesn’t cover, even when a vendor like IBM issues numerous advisories that they miss. No matter how you cut it, their numbers are invalid.
So poking at our database, understanding we don’t quite have a 100% mapping to Secunia, but feel it is pretty close, we see that around 5,280 of our entries have a Secunia reference and 4,530 of those also have a CVE reference (compared to more than 8,500 entries we have with a CVE reference). Even counting for a good margin of error, it still appears that Secunia does not cover almost 3,000 vulnerabilities in 2014, which are covered by CVE entries. Those familiar with this blog know that we are more critical of CVE than any other Vulnerability Database. If a commercial VDB with hundreds of high-dollar clients can’t even keep a 100% mapping with an over-funded, U.S. government run VDB that is considered the “lowest common denominator” by many, that speaks volumes. I could end the blog on that note alone, because anything less than mediocrity is a disgrace. How do you trust, and pay for, a vulnerability intelligence service missing thousands of publicly disclosed vulnerabilities, that are served up on a platter and available to anyone for free use and inclusion in their own database? You don’t. After all, remember this quote from the Secunia report last year?
CVE has become a de facto industry standard used to uniquely identify vulnerabilities, which have achieved wide acceptance in the security industry.
All of the above is not only important, it is absolutely critical to appropriately frame their statistics. Not only does Secunia avoid using the minimum industry standard for vulnerability aggregation, they opt to use their own methodology, which they now know beyond doubt seriously inflates their ‘vulnerability’ count. Last year, it was by almost three times more than reality. This year, it was also by about three times more than reality, as they only covered approximately 5,500 unique vulnerabilities. That is almost 3,000 less than CVE and 8,000 less than OSVDB. Any excuses of Secunia coverage lacking that are based on them claiming to verify vulnerabilities and “not covering vulnerabilities in beta software” are also invalid, as a majority of vulnerabilities reported are in stable software, and regularly come from trusted researchers or the vendors themselves. Regardless, it should be clear to anyone passingly familiar with the aggregation of vulnerabilities that Secunia is playing well outside the bounds of reality. Of course, every provider of vulnerability intelligence has some motive, or at least desire, to see the numbers go up year to year. It further justifies their customers spending money on the solution.
“Every year, we see an increase in the number of vulnerabilities discovered, emphasizing the need for organizations to stay on top of their environment. IT teams need to have complete visibility of the applications that are in use, and they need firm policies and procedures in place, in order to deal with the vulnerabilities as they are disclosed.” — Kasper Lindgaard, Director of Research and Security at Secunia.
While Mr. Lindgaard’s quote is flashy and compelling, it is also completely wrong, even according to their own historical reports. If Mr. Lindgaard had read Secunia’s own report from 2010 and 2011, he might have avoided this blunder.
This report presents global vulnerability data from the last five years and identifies trends found in 2010. The total number of vulnerabilities disclosed in 2010 shows a slight decrease of 3% compared to 2009. – Yearly Report 2010 (Secunia)
Analysing the long-term and short-term trends of all products from all vendors in the Secunia database over the last six years reveals that the total number of vulnerabilities decreased slightly in 2011 compared to 2010. – Vulnerabilities are Resilient (2011, Secunia Report)
In 2007 OSVDB cataloged 9,574 vulnerabilities as compared to 11,050 in 2006. In 2009 they cataloged 8,175 vulnerabilities as compared to 9,807 in 2008. In 2011 they cataloged 7,913 vulnerabilities compared to 9,161 in 2010. That is three distinct years that were not an increase at all. Taking Mr. Lindgaard’s quote into account, and comparing it to our own data that is based on a more standard method of abstraction, we also show that it has not been a steady rise every year:
With highly questionable statistics, based on a flawed methodology, Secunia also lucked out this year, as vendors are more prudent about reporting vulnerabilities in used third-party libraries (e.g. OpenSSL, PHP). This plays out nicely for a company that incorrectly counts each vendor’s use of vulnerable software as a distinct issue.
Getting down to the statistics they share, we’ll give a few additional perspectives. As with all vulnerability statistics, they should be properly explained and disclaimed, or they are essentially meaningless.
In 2014, a total of 15,435 vulnerabilities were discovered in 3,870 products from 500 vendors.
As stated previously, this is absolutely false. Rather than track unique vulnerabilities, Secunia’s model and methodology is to focus more on products and operating systems. For example, they will issue one advisory for a vulnerability in OpenSSL, then dozens of additional advisories for the exact same vulnerability. The only difference is that each subsequent advisory covers a product or operating system that uses it. Above I mentioned the redundant ‘HeartBleed’ entries, but to further illustrate the point and demonstrate how this practice can lead to wildly inaccurate statistics, let’s examine the OpenSSL ‘FREAK’ vulnerability as well (29 Secunia advisories). The flaw is in the OpenSSL code, not the implementation from each vendor, so it is still that same one vulnerability. Depending on how good their coverage is, this could be more problematic. Looking at IBM, who uses OpenSSL in a wide variety of their products, we know that at least 56 are impacted by the vulnerability, which may mean that many more Secunia advisories cover them. If we had a perfect glimpse into what products use OpenSSL, it would likely be thousands. Trying to suggest that is ‘thousands of unique vulnerabilities’ is simply ignorant.
83% of vulnerabilities in all products had patches available on the day of disclosure in 2014.
We assume that by ‘patches’, they mean a viable vendor-provided solution (e.g. upgrade) as well. Based on our aggregation, it is closer to 64% that have a solution available, and that is not counting “the day of disclosure”. That includes vendors who have patched since the issue was disclosed. This big gap comes from the number of vulnerabilities aggregated by each database since the start of 2014.
25 zero-day vulnerabilities were discovered in total in 2014, compared to 14 the year before.
Assuming we use the same definition of “zero-day” as Secunia, this is considerably under what we tracked. We flag such issues “discovered in the wild”, meaning the vulnerability was being actively exploited by attackers when it was discovered and/or disclosed. In 2014, we show 43 entries with this designation, compared to 73 in 2013. That is a sharp decrease, not increase. Part of that large swing for us comes from a rash of attacker-trojaned software distributions that were used to target mobile users in 2013. Since trojaned software from a legitimate vendor meets the criteria to be called a vulnerability (it can be abused by a bad actor to cross privilege boundaries), we include it where Secunia and other databases generally ignore it.
20 of the 25 zero-day vulnerabilities were discovered in the 25 most popular products – 7 of these in operating systems.
Since we got into the “popular products” bit in last year’s rebuttal to their statistics, we’ll skip that this year. However, in 2014 we show that 16 of those “zero day” were in Microsoft products (two in Windows, six in the bundled MSIE), and four were in Adobe products.
In 2014, 1,035 vulnerabilities were discovered in the 5 most popular browsers: Google Chrome, Mozilla Firefox, Internet Explorer, Opera and Safari. That is a 42% increase from 2013.
Without searching our data, it is likely very safe to say these numbers are way off, and that Secunia’s coverage of browser security is woefully behind. In addition to not aggregating as much data, they likely don’t properly take into account vulnerabilities in WebKit, which potentially affects Chrome, Safari, and Opera. Are WebKit vulnerabilities attributed to one, the other, or all three? With that in mind, let’s compare numbers. We see ~200 for Mozilla, ~250 for Microsoft IE, and not even 10 between Safari and Opera. In reality, Opera is not forthcoming in their information about vulnerabilities they patch, so their actual vulnerability count is likely much higher. That leaves us with Chrome, which had over 300 vulnerabilities in their own code. As mentioned, factor in another 100+ vulnerabilities in WebKit that may impact up to three browsers. That comes to a total of 889, far less than their claimed 1,035. That makes us curious if they are using the same flawed methodology with browser vulnerabilities, as they do with libraries (i.e. counting WebKit / Blink issues multiple times for each browser using it). Some vulnerabilities in these browsers are also due to flaws in other 3rd party libraries and not in the browsers’ own code (e.g. ICU4C and OpenJPEG). Finally, Google Chrome provides Adobe Flash Player, so is Secunia adding the number of vulnerabilities addressed in Flash Player to their Google Chrome count as well, further bloating it? So many unknowns and another reminder of why vulnerability statistics are often misleading or serve no value. Without explaining the methodology, we’re left with guesses and assumptions that strongly suggest this statistic can’t be trusted.
Even more offensive, is that the “vulnerability intelligence experts at Secunia Research” don’t demonstrate any expertise in informing readers why Google Chrome numbers are so high. Instead, they publish the information, withhold details of the methodology, and let the media run wild parroting their pedestrian statistics and understanding. As a lesson to the media, and Secunia, consider these additional pieces of information that help explain those numbers, and why you simple can’t compare disclosed vulnerability totals:
Google releases details about the vulnerabilities fixed in Chrome, unlike some other browser vendors. For example, Opera releases almost no information. Microsoft typically releases information on the more serious vulnerabilities, and none from their internal auditing. Of the 310 Chrome vulnerabilities we tracked, 66 were CVSSv2 5.0 or less.
Google has perhaps the most aggressive bug bounty program in the industry, which encourages more researchers to audit their code. How aggressive? They paid out more than US$550,000 in 2014, just for Chrome vulnerabilities.
Google’s turnaround in fixing Chrome vulnerabilities is quite respectable. Since many of the vulnerabilities were reported to them and fixed promptly, it is easy to argue with the claim it is the “least secure” browser.
Google fields several teams of security experts that audit their code, including Chrome. They find and fix potential issues before disclosing them. By doing that, they are ensuring the security of the browser, yet effectively getting punished by Secunia for doing so.
In addition to all of the issues disclosed, a tiny fraction were actually proven to be exploitable. Like many software vendors, they find it is easier and more efficient to spend a small amount of time to fix the possible vulnerability rather than the larger amount of time required to prove it is exploitable.
Vulnerability statistics can be useful. But they must be presented in a responsible and educated manner to serve their purpose. Those not familiar with vulnerability aggregation and generating the resulting statistics typically do a poor job, and add confusion to the matter. We like to call such people “vulnerability tourists”, and we can now add Secunia to the growing list of them.
[Update: 2015-04-01. One additional quote from the 2010 Secunia Report was added, and clarification of wording regarding the yearly vulnerability total chart was made.]
[This was originally published on the OSVDB blog.]
Nothing like waking up to a new article purporting to show vulnerability statistics and having someone ask us for comment. But hey, we love giving additional perspective on such statistics since they are often without proper context and disclaimers. This morning, the new article comes from Help Net Security and is titled “SQL injection vulnerabilities surge to highest levels in three years“. It cites “DB Networks’ research” who did the usual, parsed NVD data. As we all know, that data comes from CVE who is a frequent topic of rant on Twitter and occasional blogs. Cliff notes: CVE does not promise comprehensive coverage of public disclosures. They openly admit this and Steve Christey has repeatedly said that CVE may not be the best for statistics, even as far back as 2006. Early in 2013, Christey again publicly stated that CVE “can no longer guarantee full coverage of all public vulnerabilities.” I bring this up to remind everyone, again, that it is important to add such disclaimers about your data set, and ultimately your published research.
Now that we know they have a vested interest in the results of their analysis coming out a specific way, let’s look at the results. First, the Help Net Security article does not describe their methodology, at all. Reading their self-written, paid-for news announcement (PR Newswire) about the analysis, it becomes very clear this is a gimmick for advertising, not actual vulnerability statistics research. It’s 2015, years after Steve Christey and I have both ranted about such statistics, and they don’t explain their methodology. This makes it apparent that “CVE abstraction bias” is possibly the biggest factor here. I have blogged about using CVE/NVD as a dataset before, because it contains one of the biggest pitfalls in such statistic generation.
Rather than debunk these stats directly, since it has been done many times in the past, I can say that they are basically meaningless at this point. Even without their methodology, I am sure someone can trivially reproduce their results and figure out if they abstracted per CVE, or per actual SQLi mentioned. As a recent example, CVE-2014-7137 is a single entry that actually covers 54 distinct SQL injection vulnerabilities. If you count just the CVE candidate versus the vulnerabilities that may be listed within them, your numbers will vary greatly. That said, I will assume that their results can be reproduced since we know their data source and their bias in desired results.
With that in mind, let’s first look at what the numbers look like when using a database that clearly abstracts those issues, and covers a couple thousand sources more than CVE officially does:
“SQL Injection Vulnerabilities Surge to Highest Levels in Three Years” is the title of DB Networks’ press release, and is summarized by Help Net Security as “last year produced the most SQL vulnerabilities identified since 2011 and 104% more than were identified in 2013.” In reality (or at least, using a more comprehensive data set), we see that isn’t the case since the available statistics a) don’t show 2014 being more than 2011 and b) 2011 not holding a candle to 2010. No big surprise really, given that we actually do vulnerability aggregation while NVD and DB Networks does not. But really, I digress. These ‘statistics’ are nothing more than a thinly veiled excuse to further advertise themselves. Notice in the press release they go from the statistics that help justify their products right into the third paragraph quoting the CEO being “truly honored to be selected as a finalist for SC Magazine’s Best Database Security Solution.” He follows that up with another line calling out their specific product that helps “database security in some of the world’s largest mission critical datacenters.“
Yep, these statistics are very transparent. They are based on a convenient data source, maintained by an agency that doesn’t actually aggregate the information, that doesn’t have the experience their data-benefactors have (CVE). They are advertised with a single goal in mind; selling their product. The fact they use the word “research” in the context of generating these statistics is a joke.
As always, I encourage companies and individuals to keep publishing vulnerability statistics. But I stress that it should be done responsibly. Disclaim your data source, explain your methodology, be clear if you are curious about the results coming out one way (bias is fine, just disclaim it), and realize that different data sources will produce different results. Dare to use multiple sources and compare the results, even if it doesn’t fully back your desired opinion. Why? Because if you disclaim your data sources and results, the logical and simple conclusion is that you may still be right. We just don’t have the perfect vulnerability disclosure data source yet. Fortunately, some of us are working harder than others to find that unicorn.
[This was originally published on the OSVDB blog.]
On February 26, Secunia released their annual vulnerability report (link to report PDF) summarizing the computer security vulnerabilities they had cataloged over the 2013 calendar year. For those not familiar with their vulnerability database (VDB), we consider them a ‘specialty’ VDB rather than a ‘comprehensive’ VDB (e.g. OSVDB, X-Force). They may disagree on that point, but it is a simple matter of numbers that leads us to designate them as such. That also tends to explain why some of our conclusions and numbers are considerably different and complete than theirs.
In past years this type of blog post would not need a disclaimer, but it does now. OSVDB, while the website is mostly open to the public, is also the foundation of the VulnDB offering from our commercial partner and sponsor Risk Based Security (RBS). As such, we are now a direct competitor to Secunia, so any criticism leveled at them or their report may be biased. On the other hand, many people know that I am consistently critical of just about any vulnerability statistics published. Poor vulnerability statistics have plagued our industry for a long time. So much so that Steven Christey from CVE and I gave a presentation last year at the BlackHat briefings in Las Vegas on the topic.
One of the most important messages and take-aways from that talk is that all vulnerability statistics should be disclaimed and explained in advance. That means that a vulnerability report should start out by explaining where the data came from, applicable definitions, and the methodology of generating the statistics. This puts the subsequent statistics in context to better explain and disclaim them, as a level of bias enters any set of vulnerability statistics. Rather than follow the Secunia report in the order they publish them, I feel it is important to skip to the very end first. For that is where they finally explain their methodology to some degree, which is absolutely critical in understanding how their statistics were derived.
On page 16 (out of 20) of the report, in the Appendix “Secunia Vulnerability Tracking Process”, Secunia qualifies their methodology for counting vulnerabilities.
A vulnerability count is added to each Secunia Advisory to indicate the number of vulnerabilities covered by the Secunia Advisory. Using this count for statistical purposes is more accurate than counting CVE identifiers. Using vulnerability counts is, however, also not ideal as this is assigned per advisory. This means that one advisory may cover multiple products, but multiple advisories may also cover the same vulnerabilities in the same code-base shared across different programs and even different vendors.
First, the ‘vulnerability count’ referenced is not part of a public Secunia advisory, so their results cannot be realistically duplicated. The next few lines are important, as they invalidate the Secunia data set for making any type of real conclusion on the state of vulnerabilities. Not only can one advisory cover multiple products, multiple advisories can cover the same single vulnerability, just across different major versions. This high rate of duplicates and lack of unique identifiers make the data set too convoluted for meaningful statistics.
CVE has become a de facto industry standard used to uniquely identify vulnerabilities which have achieved wide acceptance in the security industry.
This is interesting to us because Secunia is not fully mapped to CVE historically. Meaning, there are thousands of vulnerabilities that CVE has cataloged, that Secunia has not included. CVE is a de facto industry standard, but also a drastically incomplete one. At the bare minimum, Secunia should have a 100% mapping to them and they do not. This further calls into question any statistics generated off this data set, when they knowingly ignore such a large number of vulnerabilities.
From Remote From remote describes other vulnerabilities where the attacker is not required to have access to the system or a local network in order to exploit the vulnerability. This category covers services that are acceptable to be exposed and reachable to the Internet (e.g. HTTP, HTTPS, SMTP). It also covers client applications used on the Internet and certain vulnerabilities where it is reasonable to assume that a security conscious user can be tricked into performing certain actions.
Classification for the location of vulnerability exploitation is important as this heavily factors into criticality; either via common usage, or through scoring systems such as CVSS. In their methodology, we see that Secunia does not make a distinction between ‘remote’ and ‘context-dependent’ (or ‘user-assisted’ by some). This means that the need for user interaction is not factored into an issue and ultimately, scoring and statistics become based on network, local (adjacent) network, or local vectors.
Secunia further breaks down their classification in the appendix under “Secunia Vulnerability Criticality Classification“. However, it is important to note that their breakdown does not really jibe with any other scoring system. Looking past the flaw of using the word ‘critical’ in all five classifications, the distinction between ‘Extremely Critical’ and ‘Highly Critical’ is minor; it appears to be solely based on if Secunia is aware of exploit code existing for that issue based on their descriptions. This mindset is straight out of the mid 90s in regards to threat modeling. In today’s landscape, if details are available about a vulnerability then it is a given that a skilled attacker can either write or purchase a vulnerability for the issue within a few days, for a majority of disclosed issues. In many cases, even when details aren’t public but a patch is, that is enough to reliably reverse it and leverage it for working exploit code in a short amount of time. Finally, both of these designations still do not abstract on if user interaction is required. In each case, it may or may not be. In reality, I imagine that the difference between ‘Extremely’ and ‘Highly’ is supposed to be based on if exploits are happening in the wild at time of disclosure (i.e. zero day).
Now that we have determined their statistics cannot be reproduced, use a flawed methodology, and are based on drastically incomplete data, let’s examine their conclusions anyway!
The blog announcing the report is titled “1,208 vulnerabilities in the 50 most popular programs – 76% from third-party programs” and immediately calls into question their perspective. Reading down a bit, we find out what they mean by “third-party programs”:
“And the findings in the Secunia Vulnerability Review 2014 support that, once again, the biggest vulnerability threat to corporate and private security comes from third-party – i.e. non-Microsoft – programs.”
Unfortunately, this is not the definition of a third-party program by most in our industry. On a higher more general level, a “third-party software component” is a “is a reusable software component developed to be either freely distributed or sold by an entity other than the original vendor of the development platform” (Wikipedia). In the world of VDBs, we frequently refer to a third-party component a ‘library‘ that is integrated into a bigger package. For example, Adobe Reader 10 which is found on many desktop computers is actually built on Adobe’s own code, but also as many as 212 other pieces of software. The notion that “non-Microsoft” software is “third-party” is very weird for lack of better words, and shows the mindset and perspective of Secunia. This completely discounts users of Apple, Linux, VMs (e.g. Oracle, VMware, Citrix), and mobile devices among others. Such a Microsoft-centric report should clearly be labeled as such, not as a general vulnerability report.
In the Top 50 programs, a total of 1,208 vulnerabilities were discovered in 2013. Third-party programs were responsible for 76% of those vulnerabilities, although these programs only account for 34% of the 50 most popular programs on private PCs. The share of Microsoft programs (including the Windows 7 operating system) in the Top 50 is a prominent 33 products – 66%. Even so, Microsoft programs are only responsible for 24% of the vulnerabilities in the Top 50 programs in 2013.
This is aiming for the most convoluted summary award apparently. I really can’t begin to describe how poorly this comes across. If you want to know the ‘Top 50 programs’, you have to read down to page 18 of the PDF and then resolve a lot of questions, some of which will be touched on below. When you read the list, and see that several ‘Microsoft’ programs actually had 0 vulnerabilities, it will call into question the “prominent 33 products” and show how the 66% is incorrectly weighted.
“However, another very important security factor is how easy it is to update Microsoft programs compared to third-party programs.” — Secunia CTO, Morten R. Stengaard.
When debunking vulnerability statistics, I tend to focus on the actual numbers. This is a case where I simply have to branch out and question how a ‘CTO’ could make this absurd statement. In one sentence, he implies that updating Microsoft is easy, while third-party programs (i.e. non-Microsoft programs per their definition) are not. Apparently Mr. Stengaard does not use Oracle Java, Adobe Flash player, Adobe Air, Adobe Reader, Mozilla Firefox, Mozilla Thunderbird, Google Chrome, Opera, or a wide range of other non-Microsoft desktop software, all of which have the same one-click patching/upgrade ability. Either Mr. Stengaard is not qualified to speak on this topic, or he is being extremely disingenuous in his characterization of non-Microsoft products to suit the needs of supporting this report and patch management business model. If he means that patching Windows is easier on an enterprise scale (e.g. via SCCM or WSUS), then that is frequently true, but such qualifications should be clear.
This is a case where using a valid and accepted definition of ‘third-party programs’ (e.g. a computing library) would make this quote more reasonable. Trying to upgrade ffmpeg, libav, or WebKit in the context of the programs that rely on them as libraries is not something that can be done by the average user. The problem is further compounded when portions of desktop software are used as a library in another program, such as AutoCad which appears in the Adobe Reader third-party license document linked above. However, these are the kinds of distinctions that any VDB should be fully aware of, and be able to disclaim and explain more readily.
Moving on to the actual ‘Secunia Vulnerability Review 2014‘ report, the very first line opens up a huge can of worms as the number is incorrect and entirely misleading. The flawed methodology used to generate the statistic cascades down into a wide variety of other incorrect conclusions.
The absolute number of vulnerabilities detected was 13,073, discovered in 2,289 products from 539 vendors.
It is clear that there are a significant amount of vulnerabilities that are being counted multiple times. While this number is generated from Secunia’s internal ‘vulnerability count’ number associated with each advisory, they miss the most obvious flaw; that many of their advisories cover the exact same vulnerability. Rather than abstract so that one advisory is updated to reflect additional products impacted, Secunia will release additional advisories. This is immediately visible in cases where a protocol is found to have a vulnerability, such as the “TLS / DTLS Protocol CBC-mode Ciphersuite Timing Analysis Plaintext Recovery Cryptanalysis Attack” (OSVDB 89848). This one vulnerability impacts any product that implements that protocol, so it is expected to be widespread. As such, that one vulnerability tracks to 175 different Secunia advisories. This is not a case where 175 different vendors coded the same vulnerability or the issue is distinct in their products. This is a case of a handful of base products (e.g. OpenSSL, GnuTLS, PolarSSL) implementing the flawed protocol, and hundreds of vendors using that software bundled as part of their own.
While that is an extreme example, the problem is certainly front-and-center due to their frequent multi-advisory coverage of the same issue. Consider that one OpenSSL vulnerability may be covered in 11 Secunia advisories. Then look at other products that are frequently used as libraries or found on multiple Linux distributions, each of which get their own advisory. Below is a quick chart showing examples of a single vulnerability in one of several products, along with the number of Secunia advisories that references that one vulnerability:
This problem is further compounded when you consider the number of vulnerabilities in those products in 2013, where each one received multiple Secunia advisories. This table shows the products from above, and the number of unique vulnerabilities as tracked by OSVDB for that product in 2013 that had at least one associated Secunia advisory:
# of Vulns in product in 2013 w/ Secunia Ref
Ruby on Rails
It is easy to see how Secunia quickly jumped to 13,073 vulnerabilities while only issuing 3,327 advisories in 2013. If there is any doubt about vulnerability count inflation, consider these four Secunia advisories that cover the same set of vulnerabilities, each titled “WebSphere Application Server Multiple Java Vulnerabilities“. Secunia created four advisories for the same vulnerabilities simply to abstract based on the major versions affected, as seen in this table:
The internal ‘vulnerability count’ for these advisories are very likely 25, 25, 25, and 27, adding up to 102. Applied against IBM, you have 27 vulnerabilities inflated greatly and counting for 102 instead. Then consider that IBM has several hundred products that use Java, OpenSSL, and other common software. It is easy to see how Secunia could jump to erroneous conclusions:
The 32% year-on-year increase in the total number of vulnerabilities from 2012 to 2013 is mainly due to a vulnerability increase in IBM products of 442% (from 772 vulnerabilities in 2012 to 4,181 in 2013).
The next set of statistics is convoluted on the surface, but even more confusing when you read the details and explanations for how they were derived:
Numbers – Top 50 portfolio The number of vulnerabilities in the Top 50 portfolio was 1,208, discovered in 27 products from 7 vendors plus the most used operating system, Microsoft Windows 7.
To assess how exposed endpoints are, we analyze the types of products typically found on an endpoint. Throughout 2013, anonymous data has been gathered from scans of the millions of private computers which have the Secunia Personal Software Inspector (PSI) installed. Secunia data shows that the computer of a typical PSI user has an average of 75 programs installed on it. Naturally, there are country- and region-based variations regarding which programs are installed. Therefore, for the sake of clarity, we chose to focus on a representative portfolio of the 50 most common products found on a typical computer and the most used operating system, and analyze the state of this portfolio and operating system throughout the course of 2013. These 50 programs are comprised of 33 Microsoft programs and 17 non-Microsoft (third-party) programs.
Reading down to page 18 of the full report, you see the table listing the “Top 50” software installed as determined by their PSI software. On the list is a wide variety of software that are either components of Windows (meaning they come installed by default, but show up in the “Programs” list e.g. Microsoft Visual C++ Redistributable) or in a few cases third-party software (e.g. Google Toolbar), many of which have 0 associated vulnerabilities. In other cases they include product driver support tools (e.g. Realtek AC 97 Update and Remove Driver Tool) or ActiveX components that are generally not installed via traditional means (e.g. comdlg32 ActiveX Control). With approximately half of the Top 50 software having vulnerabilities, and mixing different types of software components, it causes summary put forth by Secunia to be misleading. Since they include Google Chrome on the list, by their current logic, they should also include WebKit which is a third-party library wrapped into Chrome, just as they include ‘Microsoft Powerpoint Viewer’ (33) which is a component of ‘Microsoft Powerpoint’ (14) and does not install separately.
Perhaps the most disturbing thing about this Top 50 summary is that Secunia only counts 7 vendors in their list. Reading through the list carefully, you see that there are actually 10 vendors represented: Microsoft, Adobe, Oracle, Mozilla, Google, Realtek, Apple, Piriform (CCleaner), VideoLAN, and Flexera (InstallShield). This seriously calls into question any conclusions put forth by Secunia regarding their Top 50 list and challenges their convoluted and irreproducible methodology.
Rather than offer a rebuttal line by line for the rest of the report and blog, we’ll just look at some of the included statistics that are questionable, wrong, or just further highlight that Secunia has missed some vulnerabilities.
In 2013, 727 vulnerabilities were discovered in the 5 most popular browsers: Google Chrome, Mozilla Firefox, Internet Explorer, Opera and Safari.
By our count, there were at least 756 vulnerabilities in these browsers: Google Chrome (295), Mozilla Firefox (155), Internet Explorer (138), Opera (9), Apple Safari (8 on desktop, 4 on mobile), and WebKit (component of Chrome and Safari, 147). The count in Opera is likely very low though. In July 2013, Opera issued the first browser based on Blink, so it’s very likely that it has been affected by the vast majority of the Blink vulnerability fixes by Google. However, Opera is not very good at clearly reporting vulnerabilities, so this very likely accounts for the very low count that both we and Secunia have; something they should clearly have disclaimed.
In 2013, 70 vulnerabilities were discovered in the 5 most popular PDF readers: Adobe Reader, Foxit Reader, PDF-XChange Viewer, Sumatra PDF and Nitro PDF Reader.
By our count, there were at least 76 vulnerabilities in these PDF readers: Adobe Reader (69), Foxit (2), PDF-XChange (1), Sumatra (0), and Nitro (4).
The actual vulnerability count in Microsoft programs was 192 in 2013; 128.6% higher than in 2012.
Based on our data, there were 363 vulnerabilities in Microsoft software in 2013, not 192. This is up from 207 in 2012, giving us a 175.3% increase.
As in 2012, not many zero-day vulnerabilities were identified in 2013: 10 in total in the Top 50 software portfolio, and 14 in All products. A zero-day vulnerability is a vulnerability that is actively exploited by hackers before it is publicly known, and before the vendor has published a patch for it.
By that definition, which we share, we tracked 72 vulnerabilities that were “discovered in the wild” in 2013. To be fair, our number is considerably higher because we actually track mobile vulnerabilities, something Secunia typically ignores. More curious is that based on a cursory search, we find 17 of their advisories that qualify as 0-day by their definition, suggesting they do not have a method for accurately counting them: SA51820 (1), SA52064 (1), SA52116 (2), SA52196 (2), SA52374 (2), SA52451 (1), SA53314 (1), SA54060 (1), SA54274 (1), SA54884 (2), SA55584 (1), SA55611 (1), and SA55809 (1).
Find out how quickly software vendors issue fixes – so-called patches – when vulnerabilities are discovered in All products.
This comes from their “Time to Patch for all products” summary page. This statement seems pretty clear; How fast do vendors issue fixes when vulnerabilities are discovered? However, Secunia does not track that specifically! The more appropriate question that can be answered by their data is “When are patches available at or after the time of public disclosure?” These are two very different metrics. The information on this page is generated using PSI/CSI statistics. So if a vulnerability is disclosed and a fix is already available at that time, it counts as within 24 hours. It doesn’t factor in that the vendor may have spent months fixing the issue before disclosure and patch.
In conclusion, while we appreciate companies sharing vulnerability intelligence, the Secunia 2013 vulnerability report is ultimately fluff that provides no benefit to organizations. The flawed methodology and inability for them to parse their own data means that the conclusions cannot be relied upon for making business decisions. When generating vulnerability statistics, a wide variety of bias will always be present. It is absolutely critical that your vulnerability aggregation methodology be clearly explained so that results are qualified and have more meaning.
These are compiled from data from the National Vulnerability Database (NVD).
There’s your first problem, using a drastically inferior data set than is available. The next bit really invalidates the rest of the article:
On average, 13 new vulnerabilities per day were reported in 2013, for a total of 4,794 security vulnerabilities: the highest number in the last five years.
This is laughable. OSVDB cataloged 10,472 disclosed vulnerabilities for 2013 (average of 28 a day), meaning these statistics were generated with less than half of known vulnerabilities. 2013 was our third year of breaking 10,000 vulnerabilities, where the rest have a single year (2006) if any at all. Seriously; what is the point of generating statistics when you knowingly use a data set lacking so much? Given that 2012 was another ’10k’ year, the statement about it being the highest number in the last five years is also wrong.
Around one-third of these vulnerabilities were classified ‘high severity’, meaning that an exploit for these vulnerabilities would have a high impact on the attacked systems.
By who? Who generated these CVSS scores exactly, and why isn’t that disclaimed in the article? Why no mention of the ‘CVSS 10′ scoring problem as VDBs must default to that for a completely unspecified issue? With a serious number of vulnerabilities either scored by vendors with a history of incorrect scoring, or VDBs forced to use ’10’ for unspecified issues, these numbers are completely meaningless and skewed.
The vulnerabilities were discovered in software provided by 760 different vendors, but the top 10 vendors were found to have 50% of the vulnerabilities:
I would imagine Oracle is accurate on this table, as we have cataloged 570 vulnerabilites in 2013 from them. However, the rest of the table is inaccurate because #2 is wrong. You say Cisco with 373, I say ffmpeg with 490. You say #10 is HP with 112 and I counter that WebKit had 139 (which in turn adds to Apple and Google among others). You do factor in that whole “software library” thing, right? For example, what products incorporate ffmpeg that have their own vulnerabilities? These are contenders for taking the #1 and #2 spot on the table.
Most Targeted Operating Systems in 2013
As we frequently see, no mention of severity here. Of the 363 Microsoft vulnerabilities in 2013, compared to the 161 Linux Kernel issues, impact and severity is important to look at. Privilege escalation and code execution is typical in Microsoft, while authenticated local denial of service accounts for 22% of the Linux issues (and only 1% for Microsoft).
In 2013 web browsers continued to justle – as in previous years – for first place on the list of third-party applications with the most security vulnerabilities. If Mozilla Firefox had the most security vulnerabilities reported last year and in 2009, Google Chrome had the “honor” in 2010 and 2011, it is now the turn of Microsoft Internet Explorer to lead with 128 vulnerabilities, 117 of them ‘critical’.
We already know your numbers are horribly wrong, as you don’t factor in WebKit vulnerabilities that affect multiple browsers. Further, what is with the sorting of this table putting MSIE up top despite it not being reported with the most vulnerabilities?
Sticking to just the browsers, Google Chrome had 297 reported vulnerabilities in 2013 and that does not count additional WebKit issues that very likely affect it. Next is Mozilla and then Microsoft IE with Safari at the lowest (again, ignoring the WebKit issue).