CVE-2011-4361

MediaWiki before 1.17.1 does not check for read permission before handling action=ajax requests, which allows remote attackers to obtain sensitive information by (1) leveraging the SpecialUpload::ajaxGetExistsWarning function, or by (2) leveraging an extension, as demonstrated by the CategoryTree, ExtTab, and InlineEditor extensions.

Weakness

During installation, installed file permissions are set to allow anyone to modify those files.

Affected Software

Potential Mitigations

• Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
• Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/1.html
• https://cwe.mitre.org/data/definitions/127.html
• https://cwe.mitre.org/data/definitions/81.html

References

• http://lists.wikimedia.org/pipermail/mediawiki-announce/2011-November/000104.html
• http://openwall.com/lists/oss-security/2011/11/29/12
• http://openwall.com/lists/oss-security/2011/11/29/6
• http://www.debian.org/security/2011/dsa-2366
• https://bugzilla.redhat.com/show_bug.cgi?id=758171
• https://bugzilla.wikimedia.org/show_bug.cgi?id=32616