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zlib: Buffer overflow


1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 200507-19 / zlib
Release Date July 22, 2005
Latest Revision July 22, 2005: 01
Impact high
Exploitable remote
Package Vulnerable versions Unaffected versions Architecture(s)
sys-libs/zlib < 1.2.3 >= 1.2.3 All supported architectures

Related bugreports: #99751


zlib is vulnerable to a buffer overflow which could potentially lead to execution of arbitrary code.

2.  Impact Information


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


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


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.

3.  Resolution Information


There is no known workaround at this time.


All zlib users should upgrade to the latest version:

Code Listing 3.1: Resolution

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

4.  References


Page updated July 22, 2005

Summary: This is a Gentoo Linux Security Advisory

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