Mozilla Firefox is a web browser. SeaMonkey is an open-source browser, email client, newsgroup client, IRC chat client, and HTML editor. The applications are exposed to a heap-based buffer overflow issue because they fail to perform adequate boundary checks on user-supplied data in the "libpr0n" GIF image parser, when handling color map changes in the "gif_image_header" section of the parser.
Ref:
http://www.mozilla.org/security/announce/2009/mfsa2009-56.html
09.45.18 - CVE: CVE-2009-3373
Platform: Cross Platform