FAAD2 is an open source MPEG-4 and MPEG-2 AAC decoder.
The ICST-ERCIS (Peking University) reported a heap-based buffer overflow in the decodeMP4file() function in frontend/main.c.
A remote attacker could entice a user to open a specially crafted MPEG-4 (MP4) file in an application using FAAD2, possibly leading to the execution of arbitrary code.
There is no known workaround at this time.
All FAAD2 users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=media-libs/faad2-2.6.1-r2"