libav - security update

Multiple vulnerabilities have been found in libav:

• CVE-2015-1872
  The ff_mjpeg_decode_sof function in libavcodec/mjpegdec.c in Libav before
  0.8.18 does not validate the number of components in a JPEG-LS Start Of
  Frame segment, which allows remote attackers to cause a denial of service
  (out-of-bounds array access) or possibly have unspecified other impact via
  crafted Motion JPEG data.
• CVE-2015-5479
  The ff_h263_decode_mba function in libavcodec/ituh263dec.c in Libav before
  11.5 allows remote attackers to cause a denial of service (divide-by-zero
  error and application crash) via a file with crafted dimensions.
• CVE-2016-7393
  The aac_sync function in libavcodec/aac_parser.c in Libav before 11.5 is
  vulnerable to a stack-based buffer overflow.

For Debian 7 Wheezy, these problems have been fixed in version
6:0.8.18-0+deb7u1.

We recommend that you upgrade your libav packages.

Further information about Debian LTS security advisories, how to apply
these updates to your system and frequently asked questions can be
found at: <https://wiki.debian.org/LTS&gt;