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Last week the @FFmpeg account began taunting security researchers. Foolish thing to do, as it ignores the asymmetry of their attack surface vs ours. So as an exercise I found a stack-based buffer overflow on software that he wrote. Took me ~20 mins to find it. Thread 🧵(1/5)

First, I noticed the FFMpeg account is not controlled by an active developer of FFMpeg, but apparently by several guys, one of them named Keiran. Weird, but it is not important. The keirank github user has very few commits, and none on FFMPEG, but Upipe, a video processing software from his company. So lets check his most recent commit "Validate num_delta_pocs to avoid a stack smash". (2/5)