CVE-2013-4136

ext/common/ServerInstanceDir.h in Phusion Passenger gem before 4.0.6 for Ruby allows local users to gain privileges or possibly change the ownership of arbitrary directories via a symlink attack on a directory with a predictable name in /tmp/.

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://rhn.redhat.com/errata/RHSA-2013-1136.html
• http://www.openwall.com/lists/oss-security/2013/07/16/6
• https://code.google.com/p/phusion-passenger/issues/detail?id=910
• https://github.com/phusion/passenger/blob/release-4.0.6/NEWS
• https://github.com/phusion/passenger/commit/5483b3292cc2af1c83033eaaadec20dba4dcfd9b