CVE 2009-4634
Multiple integer underflows in FFmpeg 0.5 allow remote attackers to cause a denial of service and possibly execute arbitrary code via a crafted file that (1) bypasses a validation check in vorbis_dec.c and triggers a wraparound of the stack pointer, or (2) access a pointer from out-of-bounds memory in mov.c, related to an elst tag that appears before a tag that creates a stream.
See the 
CVE page on Mitre.org
for more details.
