CVE-2012-3393 in Moodle
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in repository/lib.php in Moodle 2.1.x before 2.1.7 and 2.2.x before 2.2.4 allows remote authenticated administrators to inject arbitrary web script or HTML by renaming a repository.
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Analysis
by VulDB Data Team • 12/06/2021
The CVE-2012-3393 vulnerability represents a critical cross-site scripting flaw in the Moodle learning management system that specifically targets the repository management functionality. This vulnerability exists in Moodle versions 2.1.x prior to 2.1.7 and 2.2.x prior to 2.2.4, affecting the repository/lib.php file which handles repository-related operations. The flaw allows authenticated administrators with sufficient privileges to inject malicious web scripts or HTML content through the repository renaming mechanism, creating a persistent security risk within the platform.
The technical implementation of this vulnerability stems from inadequate input validation and output sanitization within the repository management component. When administrators rename repositories, the system fails to properly sanitize user-supplied input before storing or rendering it in web pages. This occurs because the application does not adequately escape or filter special characters that could be interpreted as HTML or JavaScript code during the repository name processing. The vulnerability is particularly dangerous because it requires only authenticated administrator access, which many organizations consider a trusted privilege level, making it easier to exploit within compromised administrative accounts.
From an operational impact perspective, this vulnerability enables attackers who have gained administrative credentials to execute arbitrary code within the context of other users' browsers. The attack vector specifically targets repository renaming functionality, which is a legitimate administrative task that would typically be performed by trusted users. However, once exploited, the injected scripts can perform actions such as stealing session cookies, redirecting users to malicious sites, or modifying repository configurations. The persistent nature of stored XSS vulnerabilities means that the malicious code remains active until the repository name is changed or the vulnerability is patched, potentially affecting all users who interact with the affected repository.
The vulnerability aligns with CWE-79, which describes cross-site scripting flaws where untrusted data is incorporated into web pages without proper sanitization. It also maps to ATT&CK technique T1059.007, which covers scripting languages including JavaScript, demonstrating how an attacker could leverage this vulnerability to execute malicious scripts. Organizations implementing Moodle should consider this vulnerability as part of their broader web application security posture, particularly given that administrative accounts often have elevated privileges and access to sensitive data. The risk is amplified by the fact that repository management is a common administrative task, making this attack vector highly accessible to attackers who have compromised administrator credentials.
Mitigation strategies for this vulnerability include immediate patching to the affected Moodle versions, implementing proper input validation and output encoding for repository names, and establishing robust administrative access controls. Organizations should also consider implementing web application firewalls to detect and block suspicious script injection attempts, along with regular security audits of administrative privileges. The recommended remediation involves upgrading to Moodle versions 2.1.7 or later for 2.1.x releases, and 2.2.4 or later for 2.2.x releases, where the input sanitization issues have been addressed through proper escaping of user-supplied repository names. Additionally, implementing principle of least privilege for administrative accounts and monitoring repository management activities can help detect potential exploitation attempts.