CVE-2008-1078

expn in the am-utils and net-fs packages for Gentoo, rPath Linux, and other distributions, allows local users to overwrite arbitrary files via a symlink attack on the expn[PID] temporary file. NOTE: this is the same issue as CVE-2003-0308.1.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Potential Mitigations

• Follow the principle of least privilege when assigning access rights to entities in a software system.
• Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/132.html
• https://cwe.mitre.org/data/definitions/17.html
• https://cwe.mitre.org/data/definitions/35.html
• https://cwe.mitre.org/data/definitions/76.html

References

• http://bugs.gentoo.org/show_bug.cgi?id=210158
• http://wiki.rpath.com/wiki/Advisories:rPSA-2008-0088
• https://issues.rpath.com/browse/RPL-2255
• http://secunia.com/advisories/29144
• http://secunia.com/advisories/29187
• http://www.securityfocus.com/bid/28044
• http://www.gentoo.org/security/en/glsa/glsa-200804-09.xml
• http://secunia.com/advisories/29694
• https://www.redhat.com/archives/fedora-package-announce/2009-January/msg00273.html
• http://secunia.com/advisories/33400
• http://www.securityfocus.com/archive/1/488931/100/0/threaded