CVE-2011-3870

Puppet 2.7.x before 2.7.5, 2.6.x before 2.6.11, and 0.25.x allows local users to modify the permissions of arbitrary files via a symlink attack on the SSH authorized_keys 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://groups.google.com/group/puppet-announce/browse_thread/thread/91e3b46d2328a1cb
• http://lists.fedoraproject.org/pipermail/package-announce/2011-October/068053.html
• http://lists.fedoraproject.org/pipermail/package-announce/2011-October/068061.html
• http://lists.fedoraproject.org/pipermail/package-announce/2011-October/068093.html
• http://secunia.com/advisories/46458
• http://www.debian.org/security/2011/dsa-2314
• http://www.ubuntu.com/usn/USN-1223-1
• http://www.ubuntu.com/usn/USN-1223-2
• https://puppet.com/security/cve/cve-2011-3870