xine-lib is a multimedia library which can be utilized to create multimedia frontends.
Heap overflows have been found in the code handling RealMedia RTSP and Microsoft Media Services streams over TCP (MMST).
By setting up a malicious server and enticing a user to use its streaming data, a remote attacker could possibly execute arbitrary code on the client computer with the permissions of the user running any multimedia frontend making use of the xine-lib library.
There is no known workaround at this time.
All xine-lib users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose media-libs/xine-lib