CVE-2015-2269 in Moodle
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in lib/javascript-static.js in Moodle through 2.5.9, 2.6.x before 2.6.9, 2.7.x before 2.7.6, and 2.8.x before 2.8.4 allow remote authenticated users to inject arbitrary web script or HTML via a (1) alt or (2) title attribute in an IMG element.
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Analysis
by VulDB Data Team • 01/26/2025
The vulnerability identified as CVE-2015-2269 represents a critical cross-site scripting flaw within the Moodle learning management system that affects multiple versions from 2.5.9 through 2.8.3. This vulnerability resides in the lib/javascript-static.js file and specifically targets the handling of image attributes during content rendering. The flaw allows authenticated users to inject malicious web script or HTML code through the alt or title attributes of IMG elements, creating a persistent security risk for Moodle installations. The vulnerability is particularly concerning because it leverages the trust relationship between authenticated users and the system, enabling attackers to execute malicious code in the context of other users' browsers.
The technical implementation of this vulnerability stems from insufficient input validation and output sanitization within the javascript-static.js module. When Moodle processes HTML content containing IMG elements with alt or title attributes, the system fails to properly sanitize these attributes before rendering them in the browser context. This inadequate filtering mechanism creates an opening for attackers to embed malicious scripts that will execute whenever other users view the affected content. The vulnerability operates under CWE-79 which classifies it as a cross-site scripting flaw due to the failure to properly escape output and validate user-supplied data. The attack vector requires an authenticated user account, making it a privilege escalation vulnerability that can be exploited by malicious insiders or compromised accounts.
The operational impact of CVE-2015-2269 extends beyond simple script injection, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, data exfiltration, and redirection to malicious sites. When authenticated users view content containing malicious IMG tags with crafted alt or title attributes, their browsers execute the injected scripts, potentially compromising their sessions and exposing sensitive educational data. The vulnerability affects Moodle installations across multiple version branches, making it particularly widespread and difficult to remediate. Organizations using Moodle for educational purposes face significant risks including potential exposure of student records, course materials, and institutional data. The attack can be particularly devastating in educational environments where users trust the system and may not recognize the malicious nature of the injected content.
Mitigation strategies for CVE-2015-2269 require immediate implementation of the vendor-provided patches and updates to affected Moodle versions. Organizations should upgrade to the patched versions 2.5.9, 2.6.9, 2.7.6, and 2.8.4 where the javascript-static.js file has been corrected to properly sanitize image attributes. Additionally, administrators should implement enhanced input validation measures and consider implementing content security policies to limit script execution capabilities. The vulnerability aligns with ATT&CK technique T1059.007 which covers scripting through web shells, and T1566 which covers spearphishing with malicious attachments, as the injected scripts could be used to establish persistent access or deliver additional payloads. Regular security audits and user access reviews should be conducted to minimize the risk of compromised accounts being used to exploit this vulnerability, while also monitoring for suspicious content uploads that might contain malicious image attributes.