GLSA 200501-02: a2ps: Multiple vulnerabilities

http://security.gentoo.org/

Severity:	normal
Title:	a2ps: Multiple vulnerabilities
Date:	01/04/2005
Bugs:	#75784, #61500
ID:	200501-02

Synopsis

The fixps and psmandup scripts in the a2ps package are vulnerable to symlink attacks, potentially allowing a local user to overwrite arbitrary files. A vulnerability in a2ps filename handling could also result in arbitrary command execution.

Background

a2ps is an Any to Postscript filter that can convert to Postscript from many filetypes. fixps is a script that fixes errors in Postscript files. psmandup produces a Postscript file for printing in manual duplex mode.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
app-text/a2ps	< 4.13c-r2	>= 4.13c-r2	All supported architectures

Description

Javier Fernandez-Sanguino Pena discovered that the a2ps package contains two scripts that create insecure temporary files (fixps and psmandup). Furthermore, we fixed in a previous revision a vulnerability in a2ps filename handling (CAN-2004-1170).

Impact

A local attacker could create symbolic links in the temporary files directory, pointing to a valid file somewhere on the filesystem. When fixps or psmandup is executed, this would result in the file being overwritten with the rights of the user running the utility. By enticing a user or script to run a2ps on a malicious filename, an attacker could execute arbitrary commands on the system with the rights of that user or script.

Workaround

There is no known workaround at this time.

Resolution

All a2ps users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=app-text/a2ps-4.13c-r2"

References

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200501-02.xml

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.