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UnZip: User-assisted execution of arbitrary code


1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 200804-06 / unzip
Release Date April 06, 2008
Latest Revision April 06, 2008: 01
Impact normal
Exploitable remote
Package Vulnerable versions Unaffected versions Architecture(s)
app-arch/unzip < 5.52-r2 >= 5.52-r2 All supported architectures

Related bugreports: #213761


A double free vulnerability discovered in UnZip might lead to the execution of arbitrary code.

2.  Impact Information


Info-ZIP's UnZip is a tool to list and extract files inside PKZIP compressed files.


Tavis Ormandy of the Google Security Team discovered that the NEEDBITS macro in the inflate_dynamic() function in the file inflate.c can be invoked using invalid buffers, which can lead to a double free.


Remote attackers could entice a user or automated system to open a specially crafted ZIP file that might lead to the execution of arbitrary code or a Denial of Service.

3.  Resolution Information


There is no known workaround at this time.


All UnZip users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=app-arch/unzip-5.52-r2"

4.  References


Page updated April 06, 2008

Summary: This is a Gentoo Linux Security Advisory

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