Adam Caudill

Security Engineer, Researcher, & Developer

  • TLS: 64bit-ish Serial Numbers & Mass Revocation

    During a recent discussion about the DarkMatter CA on a Mozilla mailing list, it was found that their 64-bit serial numbers weren’t actually 64 bits, and it opened a can of worms. It turns out that the serial number was effectively 63 bits, which is a violation of the CA/B Forum Baseline Requirements that state it must contain 64 bits of output from a secure random number generator (CSPRNG). As a result of this finding, 2,000,000 certificates or more may need to be replaced by Google, Apple, GoDaddy and various others.

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  • Bitcoin is a Cult

    The Bitcoin community has changed greatly over the years; from technophiles that could explain a Merkle tree in their sleep, to speculators driven by the desire for a quick profit & blockchain startups seeking billion dollar valuations led by people who don’t even know what a Merkle tree is. As the years have gone on, a zealotry has been building around Bitcoin and other cryptocurrencies driven by people who see them as something far grander than they actually are; people who believe that normal (or fiat) currencies are becoming a thing of the past, and the cryptocurrencies will fundamentally change the world’s economy.

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  • Exploiting the Jackson RCE: CVE-2017-7525

    Earlier this year, a vulnerability was discovered in the Jackson data-binding library, a library for Java that allows developers to easily serialize Java objects to JSON and vice versa, that allowed an attacker to exploit deserialization to achieve Remote Code Execution on the server. This vulnerability didn’t seem to get much attention, and even less documentation. Given that this is an easily exploited Remote Code Execution vulnerability with little documentation, I’m sharing my notes on it.

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  • Breaking the NemucodAES Ransomware

    The Nemucod ransomware has been around, in various incarnations, for some time. Recently a new variant started spreading via email claiming to be from UPS. This new version changed how files are encrypted, clearly in an attempt to fix its prior issue of being able to decrypt files without paying the ransom, and as this is a new version, no decryptor was available1. My friends at Savage Security contacted me to help save the data of one of their clients; I immediately began studying the cryptography related portions of the software, while the Savage Security team was busy looking at other portions.

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  • 30 Days of Brave

    Brave is a web browser available for multiple platforms that aims to provide additional security and privacy features – plus a novel monetization scheme for publishers. I gave it 30 days to see if it was worth using. I switched on all platforms I use to give it a fair shot, I normally use Chrome which made the switch less painful, though the results were very much mixed. There are some things I honestly liked about it, some things I really disliked, and at least one thing that just made me mad.

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  • Confide, Screenshots, and Imaginary Threats

    Recently Vice published a story about a lawsuit against the makers of the ‘secure’ messaging application Confide. This isn’t just a lawsuit, it’s a class-action lawsuit and brought by Edelson PC – an amazingly successful (and sometimes hated1) law firm – this isn’t a simple case. The complaint includes a very important point: Specifically, Confide fails to deliver on two of the three requirements that it espouses as necessary for confidential communications: ephemerality and screenshot protection.

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  • Shadow Brokers, Equation Group, Oh My…

    Yet again, a group known as The Shadow Brokers is in the news, with yet another leak from what is widely accepted as the NSA (Equation Group1 in APT terms). This release is, to many, the most important release of this leaked stolen material from the most elite and secretive hacking operation in the world. This is a collection of a few notes on this highly unusual operation. If you haven’t read this excellent overview of the most recent release by Dan Goodin, you should do that now.

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  • Looking for value in EV Certificates

    When you are looking for TLS (SSL) certificates, there are three different types available, and vary widely by price and level of effort required to acquire them. Which one you choose impacts how your certificate is treated by browsers; the question for today is, are EV certificates worth the money? To answer this, we need to understand what the differences are just what you are getting for your money. The Three Options For many, the choice of certificate type has more to do with price than type – and for that matter, not that many people even understand that there are real differences in the types of certificates that a certificate authority (CA) can issue.

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  • YAWAST 0.5 Released

    Today, I’ve released the latest version of YAWAST, a security scanner for web applications that provides basic information about the application, and performs common checks so that you can move on to the fun part of testing more quickly. YAWAST also remains the only tool I’ve found that can perform an accurate test for SWEET32. Here is the change log for version 0.5.0: #35 – Add check for SameSite cookie attribute #53 – Added checks for .

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  • On the need for an open Security Journal

    The information security industry, and more significantly, the hacking community are prolific producers of incredibly valuable research; yet much of it is lost to most of those that need to see it. Unlike academic research which is typically published in journals (with varying degrees of openness), most research conducted within the community is presented at a conference – and occasionally with an accompanying blog post. There is no journal, no central source that this knowledge goes to; if you aren’t at the right conference, or follow the right people on Twitter, there’s a great chance you’ll never know it happened.

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