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ncompress: Buffer overflow


1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 200410-08 / ncompress
Release Date October 09, 2004
Latest Revision May 22, 2006: 02
Impact normal
Exploitable remote
Package Vulnerable versions Unaffected versions Architecture(s)
app-arch/ncompress <= 4.2.4 >= 4.2.4-r1 All supported architectures

Related bugreports: #66251


compress and uncompress, which could be used by daemon programs, contain a buffer overflow that could lead to remote execution of arbitrary code with the rights of the daemon process.

2.  Impact Information


ncompress is a utility handling compression and decompression of Lempel-Ziv archives, compatible with the original *nix compress and uncompress utilities (.Z extensions).


compress and uncompress do not properly check bounds on command line options, including the filename. Large parameters would trigger a buffer overflow.


By supplying a carefully crafted filename or other option, an attacker could execute arbitrary code on the system. A local attacker could only execute code with his own rights, but since compress and uncompress are called by various daemon programs, this might also allow a remote attacker to execute code with the rights of the daemon making use of ncompress.

3.  Resolution Information


There is no known workaround at this time.


All ncompress users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge sync

# emerge -pv ">=app-arch/ncompress-4.2.4-r1"
# emerge ">=app-arch/ncompress-4.2.4-r1"

4.  References


Page updated October 09, 2004

Summary: This is a Gentoo Linux Security Advisory

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