If you love exploit mitigations, you may have heard of a new system call named mseal landing into the Linux kernel’s 6.10 release, providing a protection called “memory sealing.” Beyond notes from the authors, very little information about this mitigation exists. In this blog post, we’ll explain what this syscall is, including […]
We’re digging up the archives of vulnerabilities that Trail of Bits has reported over the years. This post shares the story of two such issues: a denial-of-service (DoS) vulnerability hidden in JSON Web Tokens (JWTs), and an oversight in the Linux kernel that could enable circumvention of critical kernel […]
Did you know that symbolic links (or symlinks) created through Windows Subsystem for Linux (WSL) can’t be followed by Windows? I recently encountered this rather frustrating issue as I’ve been using WSL for my everyday work over the last few months. No doubt others have noticed it as well, so I wanted […]
The Open Source Technology Improvement Fund (OSTIF) counters an often overlooked challenge in the open-source world: the same software projects that uphold today’s internet infrastructure are reliant on, in OSTIF’s words, a “surprisingly small group of people with a limited amount of time” for all development, testing, and maintenance. This scarcity of contributor time in […]
eBPF (extended Berkeley Packet Filter) has emerged as the de facto Linux standard for security monitoring and endpoint observability. It is used by technologies such as BPFTrace, Cilium, Pixie, Sysdig, and Falco due to its low overhead and its versatility. There is, however, a dark (but open) secret: eBPF was never intended […]
Despite its use for refactoring and static analysis tooling, Clang has a massive shortcoming: the Clang AST does not provide provenance information about which CPP macro expansions a given AST node is expanded from; nor does it lower macro expansions down to LLVM Intermediate Representation (IR) code. This makes the construction of […]
I discovered a logic bug in the readline dependency that partially reveals file information when parsing the file specified in the INPUTRC environment variable. This could allow attackers to move laterally on a box where sshd is running, a given user is able to login, and the user’s private key […]
Have you ever tried using LLVM’s X-Ray profiling tools to make some flame graphs, but gotten obscure errors like: ==65892==Unable to determine CPU frequency for TSC accounting. ==65892==Unable to determine CPU frequency. Or worse, have you profiled every function in an application, only to find the sum of all function runtimes accounted for ~15 minutes […]
