CVE-2011-4299 in Moodle
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in mod/wiki/pagelib.php in Moodle 2.0.x before 2.0.5 and 2.1.x before 2.1.2 allows remote authenticated users to inject arbitrary web script or HTML via a wiki comment.
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Analysis
by VulDB Data Team • 12/05/2021
The vulnerability described in CVE-2011-4299 represents a critical cross-site scripting weakness within the Moodle learning management system that affects versions prior to 2.0.5 and 2.1.2. This issue resides in the mod/wiki/pagelib.php file and specifically targets the wiki comment functionality, creating a pathway for authenticated attackers to execute malicious code within the context of other users' browsers. The vulnerability operates through a classic XSS attack vector where malicious input is not properly sanitized before being rendered in web pages, allowing attackers to inject arbitrary web scripts or HTML content. The affected system components include the wiki module's comment handling mechanism which fails to validate or escape user-supplied input before displaying it in the browser environment.
The technical exploitation of this vulnerability requires an attacker to possess valid authentication credentials within the Moodle system, as the flaw specifically targets authenticated users rather than unauthenticated access. This authentication requirement does not diminish the severity of the vulnerability, as it still allows for persistent code execution within the context of other users' sessions. The flaw directly maps to CWE-79, which defines Cross-Site Scripting as a weakness where untrusted data is incorporated into web page content without proper validation or escaping mechanisms. The vulnerability demonstrates a clear failure in input sanitization and output encoding practices that are fundamental to preventing XSS attacks in web applications.
Operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to steal session cookies, redirect users to malicious websites, deface course content, or even escalate privileges within the Moodle environment. The persistent nature of wiki comments means that once injected, malicious scripts can affect all users who view the affected wiki pages, potentially compromising multiple user sessions and course integrity. Attackers could leverage this vulnerability to create backdoors within the learning management system, access confidential student information, or manipulate course content to mislead users. The vulnerability also aligns with ATT&CK technique T1566, which covers the use of credential harvesting and session hijacking through web-based attacks, and T1059, which involves the execution of malicious code through web interfaces.
Mitigation strategies for CVE-2011-4299 require immediate patching of affected Moodle installations to versions 2.0.5 or 2.1.2, which contain the necessary input validation and output encoding fixes. Organizations should implement comprehensive input sanitization measures that validate all user-supplied data before processing, particularly for web-based content and comment fields. Regular security auditing of web applications should include thorough testing for XSS vulnerabilities, particularly in modules that handle user-generated content. Additionally, implementing Content Security Policy headers can provide an additional layer of defense by restricting script execution and preventing unauthorized code injection. Network monitoring should be enhanced to detect suspicious user behavior patterns that might indicate exploitation attempts. The vulnerability underscores the importance of maintaining up-to-date software versions and implementing robust security controls for all web-based educational platforms. Organizations should also consider implementing web application firewalls and regular security assessments to identify similar vulnerabilities that may exist in other components of their Moodle installations or related systems.