Secunia

Some vulnerabilities have been reported in Mozilla SeaMonkey, which can be exploited by malicious people to manipulate certain data or compromise a user's system.

1) An error exists when parsing regular expressions used in Proxy Auto-configuration (PAC). This can be exploited to cause a crash or potentially execute arbitrary code via specially crafted configured PAC files.

2) An error when processing GIF color maps can be exploited to cause a heap-based buffer overflow and potentially execute arbitrary code via a specially crafted GIF file.

3) An error when downloading files can be exploited to display different file names in the download dialog title bar and dialog body. This can be exploited to obfuscate file names via a right-to-left override character and potentially trick a user into running an executable file.

Solution
Update to version 1.1.19, which fixes vulnerability #3. Do not visit untrusted websites or follow untrusted links.
Further details available in Customer Area

Provided and/or discovered by
The vendor credits:
1) Marco C.
2) regenrecht, reported via iDefense
3) Jesse Ruderman and Sid Stamm

Changelog
Further details available in Customer Area

Original Advisory
Mozilla Foundation:
http://www.mozilla.org/security/announce/2009/mfsa2009-55.html
http://www.mozilla.org/security/announce/2009/mfsa2009-56.html
http://www.mozilla.org/security/announce/2009/mfsa2009-62.html

Deep Links
Links available in Customer Area