CVE-2011-1004

The FileUtils.remove_entry_secure method in Ruby 1.8.6 through 1.8.6-420, 1.8.7 through 1.8.7-330, 1.8.8dev, 1.9.1 through 1.9.1-430, 1.9.2 through 1.9.2-136, and 1.9.3dev allows local users to delete arbitrary files via a symlink attack.

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.apple.com/archives/security-announce/2012/May/msg00001.html
• http://lists.fedoraproject.org/pipermail/package-announce/2011-March/054422.html
• http://lists.fedoraproject.org/pipermail/package-announce/2011-March/054436.html
• http://osvdb.org/70958
• http://secunia.com/advisories/43434
• http://secunia.com/advisories/43573
• http://support.apple.com/kb/HT5281
• http://www.mandriva.com/security/advisories?name=MDVSA-2011:097
• http://www.openwall.com/lists/oss-security/2011/02/21/2
• http://www.openwall.com/lists/oss-security/2011/02/21/5
• http://www.redhat.com/support/errata/RHSA-2011-0909.html
• http://www.redhat.com/support/errata/RHSA-2011-0910.html
• http://www.ruby-lang.org/en/news/2011/02/18/fileutils-is-vulnerable-to-symlink-race-attacks/
• http://www.securityfocus.com/bid/46460
• http://www.vupen.com/english/advisories/2011/0539
• https://bugzilla.redhat.com/show_bug.cgi?id=678913