Articles by Christian Holler
-
Behind the Scenes Hardening Firefox with Claude Mythos Preview
Two weeks ago we announced that we had identified and fixed an unprecedented number of latent security bugs in Firefox with the help of Claude Mythos Preview and other AI models. In this post, we’ll go into more detail about how we approached this work, what we found, and advice for other projects on making […]
-
Snapshots for IPC Fuzzing
Process separation remains one of the most important parts of the Firefox security model and securing our IPC (Inter-Process Communication) interfaces is crucial to keep privileges in the different processes separated. We take a more detailed look at our newest tool for finding vulnerabilities in these interfaces – snapshot fuzzing.
-
Retrospective and Technical Details on the recent Firefox Outage
On January 13th 2022, Firefox became unusable for close to two hours for users worldwide. This incident interrupted many people’s workflow. This post highlights the complex series of events and circumstances that, together, triggered a bug deep in the networking code of Firefox.
-
Eliminating Data Races in Firefox – A Technical Report
We successfully deployed ThreadSanitizer in the Firefox project to eliminate data races in our remaining C/C++ components. In the process, we found several impactful bugs and can safely say that data races are often underestimated in terms of their impact on program correctness. We recommend that all multithreaded C/C++ projects adopt the ThreadSanitizer tool to enhance code quality.