FFmpeg is a very fast video and audio converter.
FFmpeg contains buffer overflows in the AVI processing code.
An attacker could trigger the buffer overflows by enticing a user to load a specially crafted AVI file in an application using the FFmpeg library. This might result in the execution of arbitrary code in the context of the running application.
There is no known workaround at this time.
All FFmpeg users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-video/ffmpeg-0.4.9_p20060530"