libavcodec/pthread_frame.c in FFmpeg before 5.1.2, as used in VLC and other products, leaves stale hwaccel state in worker threads, which allows attackers to trigger a use-after-free and execute arbitrary code in some circumstances (e.g., hardware re-initialization upon a mid-video SPS change when Direct3D11 is used).
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| https://git.ffmpeg.org/gitweb/ffmpeg.git/commit/cc867f2c09d2b69cee8a0eccd62aff002cbbfe11 | mailing list patch |
| https://news.ycombinator.com/item?id=35356201 | issue tracking exploit third party advisory |
| https://wrv.github.io/h26forge.pdf | technical description |
| https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PQHNSWXFUN3VJ3AO2AEJUK3BURSGM5G2/ | vendor advisory |
| https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KOMB6WRUC55VWV25IKJTV22KARBUGWGQ/ | vendor advisory |
| https://security.gentoo.org/glsa/202312-14 | vendor advisory |