Moodle 2.3.x before 2.3.1 uses only a client-side check for whether references are permitted in a file upload, which allows remote authenticated users to bypass intended alias (aka shortcut) restrictions via a client that omits this check.

References

• https://nvd.nist.gov/vuln/detail/CVE-2012-3387
• https://exchange.xforce.ibmcloud.com/vulnerabilities/76954
• http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-33948
• http://openwall.com/lists/oss-security/2012/07/17/1
• moodle/moodle@3b6629c
• moodle/moodle@61a339e
• https://web.archive.org/web/20121104220059/http://www.securityfocus.com/bid/54481