zlib: Buffer overflow

Background

zlib is a widely used free and patent unencumbered data compression library.

Description

zlib improperly handles invalid data streams which could lead to a buffer overflow.

Impact

By creating a specially crafted compressed data stream, attackers can overwrite data structures for applications that use zlib, resulting in arbitrary code execution or a Denial of Service.

Workaround

There is no known workaround at this time.

Resolution

All zlib users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=sys-libs/zlib-1.2.3"