Potential bypass of Runas user restrictions
> When sudo is configured to allow a user to run commands as an arbitrary user via the ALL keyword in a Runas specification, it is possible to run commands as root by specifying the user ID -1 or 4294967295.
Interesting combination of circumstances.
Minerva: Lattice attacks strike again
> This page describes our discovery of a group of side-channel vulnerabilities in implementations of ECDSA/EdDSA in programmable smart cards and cryptographic software libraries. Our attack allows for practical recovery of the long-term private key. We have found implementations which leak the bit-length of the scalar during scalar multiplication on an elliptic curve. This leakage might seem minuscule as the bit-length presents a very small amount of information present in the scalar. However, in the case of ECDSA/EdDSA signature generation, the leaked bit-length of the random nonce is enough for full recovery of the private key used after observing a few hundreds to a few thousands of signatures on known messages, due to the application of lattice techniques.
How a double-free bug in WhatsApp turns to RCE
> In this blog post, I’m going to share about a double-free vulnerability that I discovered in WhatsApp for Android, and how I turned it into an RCE.
> Double-free vulnerability in DDGifSlurp in decoding.c in libpl_droidsonroids_gif
Defense at Scale
> Last year, my colleague Chris Rohlf gave a keynote at BSidesNOLA entitled “Offense at Scale”. Offense sounds fun. Pwn all the things. And you’re always going to win! And normally I’m a big fan of being massively offensive. Unfortunately, I find myself on the defense when it comes to information security.
> Here’s how you defend at scale. Can’t be done. The end. Everything’s fucked. You’re pwned.
Plenty of good points here. Also a fun read.
Remote Code Execution in Firefox beyond memory corruptions
> Browsers are complicated enough to have attack surface beyond memory safety issues. This talk will look into injection flaws in the user interface of Mozilla Firefox, which is implemented in JS, HTML, and an XML-dialect called XUL. With an Cross-Site Scripting (XSS) in the user interface attackers can execute arbitrary code in the context of the main browser application process. This allows for cross-platform exploits of high reliability. The talk discusses past vulnerabilities and will also suggest mitigations that benefit Single Page Applications and other platforms that may suffer from DOM-based XSS, like Electron.
USENIX Security '19 Technical Sessions
> The full Proceedings published by USENIX for the conference are available for download below. Individual papers can also be downloaded from the presentation page.
Tethered jailbreaks are back
> checkm8 exploits the Boot ROM to allow anyone with physical control of a phone to run arbitrary code. The Boot ROM, also called the Secure ROM, is the first code that executes when an iPhone is powered on and cannot be changed, because it’s “burned in” to the iPhone’s hardware. The Boot ROM initializes the system and eventually passes control to the kernel. It’s the root of trust for the trusted boot chain of iOS and verifies the integrity of the next stage of the boot process before passing execution control.
How Google Changed the Secretive Market for the Most Dangerous Hacks in the World
> For five years, Google has funded Project Zero, a team of hackers with the sole mission of finding bugs in whatever software they wanted to research, be it Google’s or somebody else’s. Are they making the internet safer?
A fair bit of fluff, but one solid point.
> For one, Project Zero has normalized something that years ago was more controversial: a strict 90-day deadline for companies that receive its bug reports to patch the vulnerabilities. If they don’t patch in that time frame, Google drops the bugs itself. Microsoft, in particular, was not a fan of this policy at the beginning. Today, most companies that interact with Project Zero respect that 90-day deadline as an industry standard, a tidal change in the always controversial debate on the so-called “responsible disclosure”—the idea that security researchers who find vulnerabilities should first disclose them to the affected company, so that it can fix them before the bugs are exploited by hackers. According to its own tally, around 95 percent of bugs reported by Project Zero get patched within that deadline.
Looking back at the Snowden revelations
> It’s no coincidence that this is a cryptography blog, which means that I’m not concerned with the same things as the general public. That is, I’m not terribly interested in debating the value of whistleblower laws (for some of that, see this excellent Twitter thread by Jake Williams). Instead, when it comes to Snowden’s leaks, I think the question we should be asking ourselves is very different. Namely:
> What did the Snowden leaks tell us about modern surveillance capabilities? And what did we learn about our ability to defend against them?
50 ways to leak your data: an exploration of apps’ circumvention of the Android permissions system
> This paper is a study of Android apps in the wild that leak permission protected data (identifiers which can be used for tracking, and location information), where those apps should not have been able to see such data due to a lack of granted permissions. By detecting such leakage and analysing the responsible apps, the authors uncover a number of covert and side channels in real-world use.
CPU Adventure – Unknown CPU Reversing
> We reverse-engineered a program written for a completely custom, unknown CPU architecture, without any documentation for the CPU (no emulator, no ISA reference, nothing) in the span of ten hours.
The Legitimate Vulnerability Market
> Trading of 0-day computer exploits between hackers has been taking place for as long as computer exploits have existed. A black market for these exploits has developed around their illegal use. Recently, a trend has developed toward buying and selling these exploits as a source of legitimate income for security researchers. However, this emerging “0-day market” has some unique aspects that make this particularly difficult to accomplish in a fair manner. These problems, along with possible solutions will be discussed. These issues will be illustrated by following two case studies of attempted sales of 0-day exploits.
> May 6, 2007
Terrible Ninth Circuit 230(c)(2) Ruling Will Make the Internet More Dangerous–Enigma v. Malwarebytes
> The Ninth Circuit has issued a Section 230(c)(2) opinion that creates significant problems for anti-spyware/spam/virus vendors (I’ll call them “anti-threat vendors”). The ruling will paralyze their decision-making, expose them to greater legal threats, and reduce their ability to protect consumers from unwanted software. This ruling makes the Internet less safe. I hope the Ninth Circuit will fix it via further proceedings.
> Nevertheless, the majority’s legal standard creates two obvious and significant problems. First, many spammers, virusmakers, and adware/spyware makers will claim–legitimately or not–to be direct or partial competitors with anti-threat vendors. In those situations, the threat purveyors will naturally claim that the blocking was motivated by anticompetitive animus. In fact, I would expect such anticompetitive animus claims to be routine for blocked entities, not an exception. Indeed, as the dissent noted, Zango claimed (not credibly) its adware was competitive with Kaspersky’s anti-threat software.
I would say it will be the AV companies facing bogus lawsuits who will lose the most, and probably not users, but it’s a bit of a pickle.
Chromebook U2F ECDSA vulnerability
> We discovered a vulnerability in the H1 security chip firmware concerning ECDSA signature generation. The firmware code used incompatible transfer instructions when passing a critical secret value to the cryptographic hardware block, resulting in generating secret values of a specific structure and having a significant loss of entropy in the secret value (64 bits instead of 256 bits). We confirmed that the incorrect generation of the secret value allows it to be recovered, which in turn allows the the underlying ECC private key to be obtained. Thus, attackers that have a single pair of signature and signed data can effectively compute the private key, breaking any functionality or protocols that use the key pair in question.
Experimental feature, with an annoying fix. If it had been for real, quite messy.
The Enigma Machine
> The Enigma Machine was one of the centerpoints of World War II, and its cryptanalysis was one of the stepping stones from breaking codes as an art to cryptography as a science. The machine encrypted messages sent between parts of the German army – operators would type a key on its keyboard, the machine would scramble that, and a letter would light up on the top.
> This notebook simulates an Enigma Machine and visualizes how it works. The Enigma Machine is an especially neat thing to visualize because it was electromechanical. As you used it, it moved. Instead of circuit traces, it had beautiful real wires connecting its pieces.
Public Suffix List Problems
> This is a collection of thoughts from a maintainer of the Public Suffix List (PSL) about the importance of avoiding new Web Platform features, security, or privacy boundaries assuming the PSL is a good starting point.
> Equally terrifying, however, is how many providers only discovered the existence of the PSL once LE was using it to rate limit - meaning that their users were able to influence cookies and other storage without restriction, until an incidental change (wanting to get more certs) caused the server operator to realize.
Cache Attacks on CTR_DRBG
> This post presents results from our paper “Pseudorandom Black Swans: Cache Attacks on CTR_DRBG”. We illustrate how omissions in the threat model of a U.S government’s standard lead to a practical, end-to-end attack on the most popular generator contained within.
Binary symbolic execution with KLEE-Native
> KLEE is a symbolic execution tool that intelligently produces high-coverage test cases by emulating LLVM bitcode in a custom runtime environment. Yet, unlike simpler fuzzers, it’s not a go-to tool for automated bug discovery. Despite constant improvements by the academic community, KLEE remains difficult for bug hunters to adopt. We’re working to bridge this gap!
> My internship produced KLEE-Native; a version of KLEE that can concretely and symbolically execute binaries, model heap memory, reproduce CVEs, and accurately classify different heap bugs. The project is now positioned to explore applications made possible by KLEE-Native’s unique approaches to symbolic execution. We will also be looking into potential execution time speed-ups from different lifting strategies. As with all articles on symbolic execution, KLEE is both the problem and the solution.
A very deep dive into iOS Exploit chains found in the wild
> Earlier this year Google’s Threat Analysis Group (TAG) discovered a small collection of hacked websites. The hacked sites were being used in indiscriminate watering hole attacks against their visitors, using iPhone 0-day.
> There was no target discrimination; simply visiting the hacked site was enough for the exploit server to attack your device, and if it was successful, install a monitoring implant. We estimate that these sites receive thousands of visitors per week.
> TAG was able to collect five separate, complete and unique iPhone exploit chains, covering almost every version from iOS 10 through to the latest version of iOS 12. This indicated a group making a sustained effort to hack the users of iPhones in certain communities over a period of at least two years.
> I’ll investigate what I assess to be the root causes of the vulnerabilities and discuss some insights we can gain into Apple’s software development lifecycle. The root causes I highlight here are not novel and are often overlooked: we’ll see cases of code which seems to have never worked, code that likely skipped QA or likely had little testing or review before being shipped to users.
The NSA's regional Cryptologic Centers
> For many years, the US National Security Agency (NSA) was identified with its almost iconic dark-glass cube-shaped headquarters building at Fort Meade in Maryland. Only when Edward Snowden stepped forward in 2013, the public learned that there’s also a large NSA facility in Hawaii - which is actually one of four regional centers spread across the United States.