CVE-2015-4156

GNU Parallel before 20150522 (Nepal), when using (1) –cat or (2) –fifo with –sshlogin, allows local users to write to arbitrary files via a symlink attack on a temporary file.

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://lists.gnu.org/archive/html/parallel/2015-04/msg00045.html
• http://lists.gnu.org/archive/html/parallel/2015-05/msg00024.html
• http://lists.opensuse.org/opensuse-updates/2015-05/msg00090.html
• http://www.securityfocus.com/bid/74961