(RHSA-2005:569) zlib security update

Zlib is a general-purpose lossless data compression library which is used
by many different programs.

Tavis Ormandy discovered a buffer overflow affecting Zlib version 1.2 and
above. An attacker could create a carefully crafted compressed stream that
would cause an application to crash if the stream is opened by a user. As
an example, an attacker could create a malicious PNG image file which would
cause a web browser or mail viewer to crash if the image is viewed. The
Common Vulnerabilities and Exposures project assigned the name
CAN-2005-2096 to this issue.

Please note that the versions of Zlib as shipped with Red Hat Enterprise
Linux 2.1 and 3 are not vulnerable to this issue.

All users should update to these erratum packages which contain a patch
from Mark Adler which corrects this issue.