CVE-2012-3396 in Moodle
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in cohort/edit_form.php in Moodle 2.0.x before 2.0.10, 2.1.x before 2.1.7, 2.2.x before 2.2.4, and 2.3.x before 2.3.1 allows remote authenticated administrators to inject arbitrary web script or HTML via the idnumber field. NOTE: this vulnerability exists because of an incorrect fix for CVE-2012-2365.
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Analysis
by VulDB Data Team • 12/06/2021
The CVE-2012-3396 vulnerability represents a cross-site scripting flaw in the Moodle learning management system that affects multiple version branches including 2.0.x through 2.3.x. This vulnerability specifically targets the cohort/edit_form.php component and exploits a weakness in how the system handles input validation for the idnumber field. The flaw is particularly concerning because it allows authenticated administrators to execute malicious code through web script injection, creating a significant security risk for educational institutions relying on Moodle for their learning platforms.
This vulnerability stems from an improper implementation of input sanitization measures that were originally intended to address CVE-2012-2365, but the subsequent fix introduced new weaknesses in the validation process. The idnumber field in cohort management forms becomes a vector for XSS attacks when administrators with appropriate privileges submit malicious input containing script tags or other HTML content. The vulnerability operates at the application layer and requires authentication to exploit, making it particularly dangerous in environments where administrators have elevated privileges and access to user data management features.
The operational impact of this vulnerability extends beyond simple script injection as it enables attackers to potentially escalate privileges, steal session cookies, redirect users to malicious sites, or even execute arbitrary commands on the affected systems. When exploited, the vulnerability can compromise the integrity of the entire Moodle installation by allowing malicious administrators to manipulate cohort data, potentially affecting thousands of users across different courses and learning environments. The vulnerability's persistence across multiple version branches indicates a systemic issue in the input validation architecture of the Moodle platform.
Organizations should implement immediate mitigations including applying the latest security patches available for their Moodle installations, implementing strict input validation for all user-supplied data, and conducting regular security audits of administrative interfaces. The vulnerability aligns with CWE-79 which categorizes cross-site scripting flaws, and represents a specific instance of how remediation efforts can inadvertently introduce new security weaknesses. From an ATT&CK framework perspective, this vulnerability maps to the privilege escalation and persistence tactics as it allows authenticated users to execute malicious code within the application context. Security teams should also consider implementing web application firewalls and monitoring for suspicious input patterns in administrative interfaces to detect potential exploitation attempts.