libexif - several vulnerabilities

Several vulnerabilities have been discovered in the EXIF parsing code
of the libexif library, which can lead to denial of service or the
execution of arbitrary code if a user is tricked into opening a
malformed image. The Common Vulnerabilities and Exposures project identifies
the following problems:

• CVE-2007-2645
  Victor Stinner discovered an integer overflow, which may result in
  denial of service or potentially the execution of arbitrary code.
• CVE-2007-6351
  Meder Kydyraliev discovered an infinite loop, which may result in
  denial of service.
• CVE-2007-6352
  Victor Stinner discovered an integer overflow, which may result
  in denial of service or potentially the execution of arbitrary
  code.

This update also fixes two potential NULL pointer deferences.

For the old stable distribution (sarge), these problems have been
fixed in 0.6.9-6sarge2.

For the stable distribution (etch), these problems have been fixed in
version 0.6.13-5etch2.

We recommend that you upgrade your libexif packages.