CVE-2012-2364 in Moodle
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in lib/filelib.php in Moodle 2.0.x before 2.0.9, 2.1.x before 2.1.6, and 2.2.x before 2.2.3 allows remote authenticated users to inject arbitrary web script or HTML via an assignment submission with zip compression, leading to text/html rendering during a "download all" action.
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Analysis
by VulDB Data Team • 12/06/2021
The CVE-2012-2364 vulnerability represents a critical cross-site scripting flaw discovered in Moodle's file library component, specifically within the lib/filelib.php file. This vulnerability affects multiple versions of the Moodle learning management system including 2.0.x before 2.0.9, 2.1.x before 2.1.6, and 2.2.x before 2.2.3. The flaw enables authenticated attackers to execute malicious scripts within the context of other users' browsers, creating a significant security risk for educational institutions relying on this platform. The vulnerability stems from inadequate input validation and sanitization mechanisms within the file handling processes of Moodle's assignment submission system.
The technical exploitation of this vulnerability occurs through a specific attack vector involving zip compressed assignment submissions. When an authenticated user uploads a malicious zip file containing specially crafted content, the system fails to properly sanitize the file names or content during the processing phase. During subsequent "download all" operations, the system renders the malicious content as text/html, executing the embedded scripts in the context of the victim's browser session. This particular flaw demonstrates a classic XSS vulnerability pattern where user-controllable input flows through the application's processing pipeline without proper sanitization, ultimately reaching the browser rendering layer.
The operational impact of this vulnerability extends beyond simple script execution, as it allows attackers to perform various malicious activities within the Moodle environment. An attacker could potentially steal session cookies, redirect users to malicious websites, modify content displayed to other users, or even escalate privileges within the system. The authenticated nature of the attack means that attackers must first gain legitimate user credentials, but once inside the system, they can exploit this vulnerability to compromise other users. This vulnerability particularly affects educational institutions where Moodle is used for managing student assignments, course materials, and collaborative learning environments. The risk is compounded by the fact that many educational institutions may have numerous users with varying levels of access, increasing the potential attack surface.
Security practitioners should implement multiple layers of defense to mitigate this vulnerability, beginning with immediate patching of affected Moodle versions to the recommended secure releases. The CWE (Common Weakness Enumeration) classification for this vulnerability aligns with CWE-79, which specifically addresses Cross-site Scripting flaws in web applications. Organizations should also consider implementing Content Security Policy (CSP) headers to limit script execution, conducting regular security audits of uploaded content, and establishing proper input validation for all user-supplied data. From an ATT&CK framework perspective, this vulnerability maps to T1059.005 (Command and Scripting Interpreter: Visual Basic) and T1566.001 (Phishing: Spearphishing Attachment), as it enables attackers to deliver malicious scripts through seemingly legitimate assignment submissions. Additionally, implementing network monitoring and anomaly detection systems can help identify suspicious file upload patterns and potential exploitation attempts. The vulnerability underscores the critical importance of secure file handling practices and input validation in web applications, particularly those handling user-generated content in educational platforms where trust and security are paramount for protecting sensitive student information and academic integrity.