Describe CVE-2011-3937.
What is CVE-2011-3937?
The H.263 codec (libavcodec/h263dec.c) in FFmpeg 0.7.x before 0.7.12, 0.8.x before 0.8.11, and unspecified versions before 0.10, and in Libav 0.5.x before 0.5.9, 0.6.x before 0.6.6, 0.7.x before 0.7.5, and 0.8.x before 0.8.1 has unspecified impact and attack vectors related to "width/height changing with frame threads.".