CVE-2014-3551 in Moodle
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in the advanced-grading implementation in Moodle through 2.3.11, 2.4.x before 2.4.11, 2.5.x before 2.5.7, 2.6.x before 2.6.4, and 2.7.x before 2.7.1 allow remote authenticated users to inject arbitrary web script or HTML via a crafted (1) qualification or (2) rating field in a rubric.
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Analysis
by VulDB Data Team • 03/26/2022
The vulnerability CVE-2014-3551 represents a critical cross-site scripting weakness discovered in Moodle's advanced grading system, affecting multiple versions from 2.3.11 through 2.7.1. This flaw resides within the rubric implementation that handles qualification and rating fields, creating a persistent security risk for educational institutions relying on this learning management system. The vulnerability specifically targets the advanced grading functionality that allows instructors to create detailed rubrics for student assessments, making it a significant concern for academic environments where user-generated content is prevalent.
The technical flaw stems from inadequate input validation and output sanitization within the rubric qualification and rating field processing mechanisms. When authenticated users submit crafted malicious content into these fields, the system fails to properly escape or filter the input before rendering it in the user interface. This creates a classic XSS vulnerability where attackers can inject arbitrary JavaScript code or HTML elements that execute in the context of other users' browsers. The vulnerability operates through the advanced grading interface where instructors define assessment criteria and assign scores, making it particularly dangerous as it can be exploited by users with legitimate access rights.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, and data exfiltration. An attacker with access to the grading system could craft malicious rubric entries that, when viewed by other users, would execute scripts in their browsers and potentially compromise their sessions. This risk is particularly severe in educational environments where instructors and students frequently interact through grading interfaces, and where the attack could be conducted by any authenticated user with sufficient privileges to modify rubric components. The vulnerability affects the core grading functionality that is essential to academic assessment processes, making it a high-value target for exploitation.
Mitigation strategies for CVE-2014-3551 should focus on immediate patch application to the affected Moodle versions, with administrators prioritizing updates to the latest stable releases. The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws in web applications, and demonstrates characteristics consistent with ATT&CK technique T1059.007 for script injection. Organizations should implement input validation at multiple layers including client-side sanitization, server-side filtering, and proper HTML escaping mechanisms. Additionally, access controls should be reviewed to limit the scope of users who can modify rubric components, and regular security audits should be conducted to identify similar vulnerabilities in other components of the learning management system. The remediation process should include comprehensive testing to ensure that the fixes do not break existing grading functionality while maintaining the system's usability for legitimate educational purposes.