a2ps: Multiple vulnerabilities
Gentoo Linux Security Advisory
||GLSA 200501-02 / a2ps
||January 04, 2005
||May 22, 2006: 03
||local and remote
All supported architectures
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.
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
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).
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.
There is no known workaround at this time.
All a2ps users should upgrade to the latest version:
Code Listing 3.1: Resolution
# emerge --sync
# emerge --ask --oneshot --verbose ">=app-text/a2ps-4.13c-r2"