http://www.techworld.com/security/news/index.cfm?NewsID=3994-Snip-
Gentoo Linux has warned of a serious, unpatched security flaw in zlib, a compression library widely used in Linux and Unix applications. The bug could be exploited to crash any application using zlib, and possibly to run malicious code on a system, security experts warned.
Separately, exploit code has appeared for a flaw affecting older versions of Firefox, increasing the risk of active attacks on the browser.
The bug affects zlib 1.2.2, and no patch is available from the zlib project. However, several Linux and Unix vendors immediately issued their own updates for the library, including Ubuntu, Red Hat, Gentoo, Suse, Debian and FreeBSD.
http://secunia.com