Perlroth & The First (Zero-Day) Broker

I am currently reading “This Is How They Tell Me The World Ends” by Nicole Perlroth, only on page 60 in Chapter 5, so a long ways to go before completing the 471 page tome. I hit chapter 4, titled “The First Broker” and it was of specific interest to me for sure, prompting this (second) blog on the book. A broker is defined as “a person who buys and sells goods or assets for others” so I was never a vulnerability broker by that definition. I am not trying to claim to be the actual first broker of zero-days in that context at all. Instead, I would like to share a couple of my own stories that are adjacent to the topic. This is all to the best of my recollection, but my memory isn’t the best due to being a diabetic and not having it under control for several years. If anyone involved in any of these stories has a different memory please feel free to comment or reach out directly and I will update this blog accordingly.


First, I was someone who ‘brokered’ deals in the sense of trading zero-day vulnerabilities for a few years in the mid-90s. As a member of multiple hacking groups, some an actual member and some an honorary member, one of my roles in several of those groups was not writing the zero-days because I simply wasn’t a coder and did not have that skill. Instead, it was to barter and try to gain access to specific zero-days one group or member wanted and my currency was other zero-days we had. While I couldn’t code, my social network of hackers was sizable.

Some of what I was authorized to trade for was toward the goal of obtaining e.g. “any remote zero-day in $target operating system” while in other cases it was “trade anything and everything we have for $specific-zero-day“. I acted as a go-between for the groups I was in and a liaison to the general hacker scene. Many knew me to have a well-rounded vulnerability collection and we already traded more pedestrian exploits, some of which weren’t public, but definitely more circulated in such groups.

Back then it was just hackers and groups, not companies, so we didn’t have “duffel bags stuffed full of half a million dollars in cash to buy zero-day bugs” (p.49). Instead we had other zero-day bugs which were just as valuable between groups and acted as the ideal currency. Just like Perlroth describes in her book relating the story of “Jimmy Sabien” (p.43), not his real name, the vulnerabilities had serious value back then too. Some were very closely guarded, to the point of not being shared with their group. For example, Sally may have shared 99% of her exploits and zero-days with her group but held one back because it was so valuable. That one she would use sparingly herself so as not to burn it or authorize it to be traded for a vulnerability of equal value. In those rare cases I would know just enough about the vulnerability to try to arrange a trade on her behalf, sometimes never seeing the vulnerability myself.

There were rumors at the time that some hackers had sold vulnerabilities to specific agencies in European governments. There were also rumors that some were trading zero-day exploits to a European law enforcement agency as a proffer or part of a plea to avoid being charged for hacking activity. But those were just rumors at that point. To me, that was the precursor to the more financial based zero-day market.


Later in the 90s, I was one of the two founders of a startup called Repent Security Inc. (RSI or RepSec). We were three people and started by trying to be a penetration testing shop. This was still early in the world of commercial penetration testing and we were going up against companies that either had an established business reputation like a couple of the ‘Big 5’ at the time, or companies that were pioneers in the game like The Wheel Group. We also created software for securely streaming logs over an encrypted tunnel so if a system was popped, you had the logs on a remote host with timestamps including your shell histories (which didn’t have timestamps natively). That software was partially outsourced to a renowned “InfoSec luminary” who had it developed by one of his interns on a compromised .edu machine and later essentially stole the software after RSI imploded. But that story is for another day because it isn’t part of the zero-day world, it’s part of the Charlatan and Errata world.

One thing RSI had of real value was the vulnerability database that I had been maintaining since 1993. It was first maintained for the hacker group I was part of (TNo) where it was originated by other members. When I took over maintaining it I worked on further organizing it, adding several points of metadata, and expanding it. After that group drifted apart I kept maintaining it while a member of w00w00 and honorary member of ADM, where I brokered some trades. I did not maintain the databases for either of those groups which were separate from mine, but I was privy to some of their exploits and shared some of what I had. Members from both groups would frequently ask me to check my database for exploits specific to an operating system or service they were targeting, as this was before Google and Yahoo! didn’t aggregate much in the big picture. Even though a majority of vulnerabilities were posted to Bugtraq, you couldn’t just skim it quickly to determine what was there that you could use for your purpose. Someone that had them all sorted in a database with metadata was fairly valuable. To this day, many friends and colleagues still ask me to do vulnerability lookups, now with VulnDB.

Throughout my hacker days I maintained that database, and then continued to as I transitioned into a career doing penetration testing. Like Perlroth documents in her book about the early days of iDefense and the outfit that “Sabien” worked for, we all scoured Bugtraq for our information primarily. I had the benefit of several circles of hackers and hackers-turned-legit that still traded vulnerability intelligence (vuln intel). Essentially the grey market back when the currency was still vuln intel not those duffels of cash. By that point, the database that RSI had was unparalleled in the commercial world. This was initially created before and maintained during Fyodor’s Exploit World and Ken Williams’ Packetstorm. The RSI database came before the ISS XForce database, before BID, before NIST’s ICAT Metabase, and before MITRE’s CVE. More importantly, it was heavy on exploit code but light on proper descriptions or solutions, so it was geared toward penetration testing and compromising machines rather than mature vulnerability intelligence.

As RSI struggled to get penetration testing gigs and opted to work on the “Secure Remote Streaming” (SRS) product, we had taken a trip to Atlanta to talk to ISS about selling a copy of our database to their relatively new X-Force penetration testing team (I forgot who we met there other than Klaus, but I would love to remember!). That deal did not happen and we soon found ourselves in talks with George Kurtz at Ernst & Young, one of the ‘Big 5’. While most or all of the ‘Big 5’ had penetration testing teams, their reputation wasn’t the best at the time. That was primarily due to their testers frequently being traditional auditors turned penetration testers, rather than being a ‘real’ tester; someone that came up through the hacking ranks.

It is also important to remind everyone that back then these companies “did not hire hackers“. Some literally printed it in advertisements as a selling point that they did not hire and would not consort with so-called black hats. This was almost always an outright lie. Either the company knew the background of their team and lied, or they did not know the background and conveniently overlooked that their employees had zero experience on their resume around that skillset, yet magically were badass testers. Years of companies claiming this also led to what we see now, where many security professionals from that time still refuse to admit they used to hack illegally even 25 years later.

Anyway, back to George and E&Y. It made sense that a shop like that would want to get their hands on RSI’s database. If their testers were primarily from the auditor / bean-counter side of things they would not have had their own solid database. Even if they had hackers it didn’t mean they came with the same vuln intel we had. As best I recall, the negotiations went back and forth for a couple weeks and we settled on a one-time sale of the RSI database for $75,000 with the option to revisit selling ‘updates’ to it as we continued to maintain it. This would have become the first commercial vulnerability intelligence feed at the time I believe, in early 1999. Then, disaster.

The FBI raided the offices of RSI, which was my apartment. At the time that was a death sentence to a penetration tester’s career. Regardless of guilt, the optics were one of black hat / criminal hacking, and finding someone to trust you to break into their systems was not happening. RSI dissolved and I found myself struggling to find work of any kind. So I reached back out to George about the deal we had on the table that we were close to signing and said I was fine with the price, let’s do it. Suddenly, Kurtz had a change of heart.

He didn’t have a change of heart as far as doing the deal, his change was in the price. Instead of $75,000 he came back and said we could do the deal for $25,000 instead, just a third of what we had agreed to. He knew I was in a tight spot and needed the money and he took full advantage of that. This is someone who had a reputation of being a friend to hackers, someone that had bridged the gap between the business world and hackers to put together a reputable team at E&Y. He even had his name on a book about penetration testing, co-authored with names other hackers recognized. He was also very explicit that he knew I had no real power at that point and refused to budge on his one-third offer.

So when he had a chance to honor the deal we originally worked on, a chance to be a friend to a hacker, at no expense of his own? He opted to screw me. Since I was out of options and my limited savings were dwindling I had to accept the offer. That takes me full circle, via a meandering path I know, to likely making one of the largest vulnerability sales at the time. While it wasn’t a single exploit, a $25k deal that was originally set to be $75k is pretty impressive for the time. If RSI had made it, odds are we would have become a software (SRS) and vulnerability intelligence shop rather than a penetration testing shop.

Many aspects of how Perlroth describes the early days of iDefense and “Sabien’s” shop, we were already doing. With a lot fewer people than they claimed, but we were aggregating information from Bugtraq and other sources, writing exploits for some of the vulnerabilities, and then we began to try to sell that information. I guess it isn’t a big surprise I ended up in the vulnerability intelligence business eventually.

Zero-days: Two Questions from Perlroth

I am currently reading “This Is How They Tell Me The World Ends” by Nicole Perlroth, only on page 17 in Chapter 2, so a long ways to go before completing the 471 page tome. While only 17 pages in, there are already some annoyances to be sure, but the tone, scope, and feel of the book is enjoyable so far. I am not sure if I will do a full review at the end or perhaps write some blogs specific to topics like this one. It obviously didn’t take long at all to get to the point where I thought a quick blog with my perspective might be interesting to some.


At the end of Chapter 1, Perlroth summarizes what she sees as the long road ahead for her to tackle the subject of zero-day exploits. This follows her describing one dinner with a variety of security folks from all sides of the topic but seems to center around two zero-day exploit writers not answering some ‘basic’ questions like “who do you sell to?” She uses this to enumerate a list of questions around the topic of zero-day exploits that she would have to face to cover the topic thoroughly. Of the 28 questions she posed to herself, two stood out to me but requires two more to better set the stage:

Who did they sell their zero-days to?
To whom would they not?
How did they rationalize the sale of a zero-day to a foreign enemy? Or to governments with gross human rights violations?

Depending on who you ask, or when you ask them, you may be told these are simple questions and answers, very complex, or like an onion.


When you ask if an exploit broker will sell to governments with “gross human rights violations“, that gets complicated in today’s world of geopolitics while remaining much more simple as far as morals and ethics go. If gross human rights violations are the line in the sand, meaning regular human rights violations are acceptable (?), then it cuts out all of the biggest players in the game; United States, China, Russia, North Korea, and Iran. Before any of my European friends head straight to the comment section, I am not forgetting or neglecting you. Some of the European countries maintain teams that are extremely accomplished and arguably better than the countries I listed. Why? You don’t see their names being splashed in every other headline and attribution claim. Further, some of the most elite zero-day writers from the late 80’s and early 90’s were European. I used to be privy to a handful of some of those exploits and on occasion, brokered (traded, not sold) them between groups. Further, I don’t associate most European countries with the other five as far as gross human rights violations, at least not in recent history.

Since zero-day exploit writers do sell to some of those countries at least (US, CN, RU), and presumably some sell to the other two (IR, KP), now we’re talking shades of grey or onions, depending on your favorite analogy. You’re left trying to draw a line in the sand as to which human rights violations you can accept and at that point, does the question even have relevance? I don’t want to get into a pissing war over who is holier or more evil than the other because each of the five countries above has their long list of sordid atrocities.


Let’s jump back to the third question there, the notion of “foreign enemy”. This is peculiar since the book had already thrown around the term “mercenary” several times in the prologue, and that scenario answers the question simply. A mercenary sells their services to the highest bidder typically, ethics takes a seat in the trunk if it even comes along for the ride. So a simple summary is that some will sell to the highest bidder, end of story.

But does any of the above really matter? Long ago I heard a great quote that is both funny and sardonic, that I think has relevance to the other question:

“We refuse to join any organization that would have us as a member.”

If we’re discussing the notion of being involved with another group (country in this case), isn’t the ethics of selling a zero-day that you know will potentially be used against your own country a lesson in abject self examination? If you are willing to sell to such an organization, one that might cause a power outage, risk human life, or undermine security and privacy as only a nation-state can, is that the kind of organization you want to be a part of? If such an organization or country is willing to buy zero-day exploits from you to use for those purposes, is that the type of organization you want to be affiliated with?

If the answer is no, then Perlroth has the beginning of her answer. If the answer is yes, then we’re back to square mercenary. Pretty simple maybe?

Redscan’s Curious Comments About Vulnerabilities

As a connoisseur of vulnerability disclosures and avid vulnerability collector, I am always interested in analysis of the disclosure landscape. That typically comes in the form of reports that analyze a data set (e.g. CVE/NVD) and draw conclusions. This seems straight-forward but it isn’t. I have written about the varied problems with such analysis many times in the past and yet, companies that don’t operate in the world of vulnerability databases still decide to play in our mud puddle. This time is the company Redscan, who I don’t think I had heard of, doing analysis on NVD data for 2020. Risk Based Security wrote a commentary on their analysis, to which I contributed, but I wanted to keep the party going over here with a few more personal comments. Just my opinions here, as a more outspoken critic on the topic, and where I break from the day job.

I am going to focus on one of my favorite topics; vulnerability tourists. People that may be in the realm of Information Security, but don’t specifically operate day-to-day in the world of vulnerability disclosures, and more specifically to me, vulnerability databases (VDBs). For this blog, I am just going to focus on a few select quotes that made me double-take. Read on after waving to Tourist Lazlo!

“The NVD tracks CVEs logged by NIST since 1988, although different iterations of the NVD account for some variation when comparing like-for-like results over time.”

There’s a lot to unpack here, most of it wrong. First, the NVD doesn’t track anything; they are spoon-fed that data from MITRE, who manages the CVE project. Second, NIST didn’t even create NVD until over five years after CVE started. Third, CVE didn’t track vulnerabilities “since 1988”; they cherry-picked some disclosures from before 1999, when they started, and why CVE IDs start with ‘1999’. Fourth, there was only one different iteration of NVD, that was their ICAT “CVE Metabase” that ran the first year of CVE basically. According to Peter Mell, who created it, said that after starting as its own vulnerability website, “ICAT had become an archival tool for CVE standard vulnerabilities and was only updated every three or four weeks”. Then in 2005 the site relaunched with a new focus and timely updates from CVE. Despite this quote, later in their report they produce a chart that tries to show an even comparison from 1988 to 2020 despite saying it went through iterations and despite not understanding CVSS.

“The growth is also likely attributable to an increase in the number of CVE Numbering Authorities (CNAs) – of which there are now more than 150 worldwide with the power to create and publish CVEs.”

The growth in disclosures aggregated by CVE is a lot more complicated than that, and the increase in CNAs I doubt is a big factor. Of course, they say this and don’t cite any evidence despite CVE now showing who the assigning CNA was (e.g. CVE-2020-2000 is Palo Alto Networks). The data is there if you want to make that analysis but it isn’t that easy since it isn’t included in the NVD exports. That means it requires some real work scraping the CVE website since they don’t include it in their exports either. Making claims without backing them up when the data is public and might prove your argument is not good.

“Again, this is a number that will concern security teams, since zero interaction vulnerabilities are famously difficult to detect and have the potential to cause significant damage.”

This makes me think that Redscan should invent a wall, perhaps made of fire, that could detect and prevent these attacks! Or maybe a system that is designed to detect intrusions! Or even one that can prevent intrusions! This quote is one that is truly baffling because it doesn’t really come with an explanation as to what they mean, and I hope they mean something far different than what this sounds like. I hope this isn’t a fear tactic to make readers think that their managed detection service is needed. Quite the opposite; anyone who says the above probably should not be trusted to do your attack detection.

This chart heading is one of many signs that Redscan doesn’t understand CVSS at all. For a “worst of the worst” vulnerability they got several attributes right but end up with “Confidentiality [High]”. The vulnerability they describe would only be CVSSv2 7.8 (AV:N/AC:L/Au:N/C:C/I:N/A:N) and CVSSv3.1 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N). That is not the worst. If it ‘highly’ impacts confidentiality, integrity, and availability then that becomes the worst of the worst, becoming CVSSv2 10.0 and CVSSv3.1 9.8 or 10.0 depending on scope. It’s hard to understand how a security company gets this wrong until you read a bit further where they say they “selected the very ‘worst’ option for every available metric.” My gut tells me they didn’t realize you could toggle ‘High’ for more than one impact and confidentiality is the first listed.

“It is also important to note that these numbers may have been artificially reduced. Tech giants such as Google and Microsoft have to do a lot to maintain their products and services day-to-day. It is common for them to discover vulnerabilities that are not being exploited in the wild and release a quick patch instead of assigning a CVE. This may account for fewer CVEs with a network attack vector in recent years.”

This is where general vulnerability tourism comes in as there is a lot wrong here. Even if you don’t run a VDB you should be passingly familiar with Microsoft advisories, as an example. Ever notice how they don’t have an advisory with a low severity rating? That’s because they don’t publish them. Their advisories only cover vulnerabilities at a certain threshold of risk. So that means that the statement above is partially right, but for the wrong reason. It isn’t about assigning a CVE, it is about not even publishing the vulnerability in the first place. Because they only release advisories for more serious issues, it actually skews their numbers to include more remote vulnerabilities, not less, primarily on the back of “remote” issues that require user interaction such as browser issues or file parsing vulnerabilities in Office.

This quote also suggests that exploitation in the wild is a bar for assigning a CVE, when it absolutely is not. It might also be a surprise to a company like Redscan, but there are vulnerabilities that are disclosed that never receive a CVE ID.

“Smart devices designed for the mass market often contain a worrying number of vulnerabilities due to manufacturer oversight. Firmware within devices is often used by multiple vendors, meaning that any vulnerabilities in this software has the potential to result in lots of CVEs.”

Wrong again, sometimes. If it is known to be the same firmware used in multiple devices, it gets one CVE ID. The only time there are additional IDs assigned is when multiple disclosures don’t positively ID the root cause. When three disclosures attribute the same vulnerability to three different products, it stands to reason there will be three IDs. But it isn’t how CVE is designed because it artificially inflates numbers, and that is the game of others.

“The prevalence of low complexity vulnerabilities in recent years means that sophisticated adversaries do not need to ‘burn’ their high complexity zero days on their targets and have the luxury of saving them for future attacks instead.”
-vs-
“It is also encouraging that the proportion of vulnerabilities requiring high-level privileges has been on the increase since 2016. This trend means that cybercriminals need to work harder to conduct their attacks.”

So which is it? When providing buzz-quote conclusions such as these, that are designed to support the data analysis, they shouldn’t contradict each other. This goes back to what I have been saying for a long time; vulnerability statistics need qualifications, caveats, and explanations.

“Just because a vulnerability is listed in the NVD as hard to exploit doesn’t mean that attackers aren’t developing PoC code to exploit it. The key is to keep up with what’s happening in the threat landscape and respond accordingly.”

I’ll end here since this is a glowing endorsement for why vulnerability intelligence has to be more evolved than what CVE and NVD are offering. Part of the CVSS specifications include Temporal scoring and one of those attributes is Exploit Code Maturity. This is designed to specifically address the problem above; that knowing the capability of potential attackers matters. With over 21,000 vulnerabilities disclosed last year, organizations are finding that just patching based on the CVSSv3 base score isn’t enough. Sure, you patch the 10.0 / 9.8 since those are truly the worst-of-the-worst, and you patch the 9.3 / 8.8 since any random email might carry a payload. Then what? If all things are equal between vulnerabilities that impact your organization you should look to see if a patch is available (also covered by Temporal score) and if an exploit is available.

Numeric scores are not enough, you have to understand the context behind them. That CVSSv2 remote information disclosure that partially affects confidentiality by disclosing an admin password is only a 5.0. Score it under CVSSv3 and you are looking at a 9.8 because it immediately leads to privilege escalation which is factored in under that system. Heartbleed was a CVSSv2 5.0 with a functional exploit and available patch; look what hell that brought upon us. If you aren’t getting that type of metadata, reconsider your choice of vulnerability intelligence.

February 2021 Reviews

[A summary of my movie and TV reviews from last month, posted to Attrition.org, mixed in with other reviews.]


Outside the Wire (2021)
Medium: Movie (Netflix)
Rating: 1 / 5 Keep it outside your watch list
Reviewer: jericho
Reference(s): IMDB Listing || Netflix
I wanted to like this movie, I really did. But it just starts out absurd at so many levels. It feels like someone wrote the script, a second person made serious edits, a third, and so on. Until you get a cohesive plot, but missing logic throughout. An unsupervised AI in a sci-fi body, contrasted by robot “Gumps” that are idiots and can’t shoot too well, a command structure that of course sends the new guy on a crazy mission, a drone operator that knows the streets of every city apparently, and that AI who is never wrong … of course is wrong? This had potential but it was squandered.


Coyote Season 1
Medium: TV (CBS All Access)
Rating: 4/5 No moleste por favor
Reviewer: jericho
Reference(s): IMDB Listing || Amazon
If you are wondering what happened to Michael Chiklis, he’s back! This time as a just-retired Border & Customs agent that finds himself on the other side of the border trying to do right by his former partner’s family. This quickly leads him down a path where he finds himself involved in the cartel and that is just the first messy part of his new life. No car chases, no shoot-outs, just a good slow build drama worth the watch.


Underwater (2020)
Medium: Movie (Multiple)
Rating: 0.5/5 drown yourself in booze before watching
Reviewer: jericho
Reference(s): IMDB Listing || Amazon
Another disaster porn meets horror movie of sorts! And like most (all?), it’s a perfect string of coincidences and a boring recipe that advances the ‘plot’ forward. Just the right amount of suits! They are all magically the right size, even for people that have never used them! Science and physics take a backseat! T.J. Miller, the bad writer’s comic crutch, who literally has to say a ‘funny’ line every single time! Ending? Predictable, stupid, and a bad attempt to get philosophical (?) making it that much worse. Skip this trash.


The Next Three Days (2010)
Medium: Movie (Netflix)
Rating: 4.5/5 … are pretty dramatic
Reviewer: jericho
Reference(s): IMDB Listing || Amazon
Russell Crowe, Elizabeth Banks, Olivia Wilde, Aisha Hinds, Jason Beghe, Lennie James, and a cameo by Liam Neeson… and I missed this movie? Maybe bad previews originally? I’m glad this popped up on Netflix’ recommendations; this as a well-done movie. Simple plot, but great casting, and fed you enough morsels to string you along to make you anticipate how it would end. This movie delivered all around with flawed but real characters at every turn and the willingness to leave some threads unpulled, where other movies might have wasted time on it.


Seungriho / Space Sweepers (2021)
Medium: Movie (Netflix)
Rating: 4.5/5 Modern space cyberpunk
Reviewer: jericho
Reference(s): IMDB Listing || Netflix
Set in 2092, with Earth on its last legs, we start out following a rag-tag crew of a ship that tries to collect space debris, which they can sell for cash. Barely scraping by, each living the life for their own reason and varied past, the money to get them out of poverty is always out of reach. When they find a surprise in junk they collect, it starts a crazy adventure that promises money they could only dream of. This South Korean movie has excellent production value, good acting, an aggressive plot, and brings the feel of a future that is part dystopia, part cyberpunk. The only challenge was keeping up with the subtitles during the fast-pace scenes. This is a fun ride with a good dose of the feels.


Silk Road (2021)
Medium: Movie (Apple)
Rating: 2/5 Long and meandering like its namesake
Reviewer: jericho
Reference(s): IMDB Listing || Apple TV
This is the 2021 movie, not the 2017 movie, about the Silk Road marketplace and the person behind it. The actual story is fascinating and full of suspense and drama. The impact the Silk Road marketplace had on part of the world for a while was incredible. This movie adaptation was probably fairly accurate, but also fairly dull for anyone already familiar with the subject matter. If you don’t know about the marketplace and saga around it, you will probably enjoy this movie a bit more.