CVE-2012-2362 in Moodle
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in blog/lib.php in the blog implementation in Moodle 1.9.x before 1.9.18, when Internet Explorer is used, allows remote attackers to inject arbitrary web script or HTML via a crafted parameter to blog/index.php.
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Analysis
by VulDB Data Team • 12/06/2021
The vulnerability described in CVE-2012-2362 represents a critical cross-site scripting flaw within the Moodle learning management system's blog component. This issue specifically affects Moodle versions 1.9.x prior to 1.9.18 and demonstrates how web application security can be compromised through improper input validation and output encoding mechanisms. The vulnerability manifests when Internet Explorer browsers are used, highlighting the importance of browser-specific security considerations in web application development and the potential for vendor-specific exploitation vectors.
The technical flaw resides in the blog/lib.php file where the application fails to properly sanitize user input parameters before rendering them in web pages. When a malicious actor crafts a specific parameter and submits it to blog/index.php, the application processes this input without adequate validation or encoding, allowing arbitrary JavaScript code or HTML content to be executed within the context of other users' browsers. This occurs because the application does not implement proper output encoding mechanisms to prevent the injection of malicious scripts into web pages served to legitimate users. The vulnerability specifically leverages the way Internet Explorer handles certain HTML and script elements, making it particularly dangerous in environments where this browser is predominant.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it enables attackers to execute malicious code in the context of authenticated users' sessions. This creates opportunities for session hijacking, privilege escalation, and data exfiltration from the Moodle environment. Attackers could potentially gain access to sensitive educational data, manipulate course content, or establish persistent backdoors within the learning management system. The vulnerability affects the core functionality of Moodle's blog feature, which is widely used by educational institutions, making it a particularly attractive target for attackers seeking to compromise educational platforms. The impact is amplified in environments where Moodle serves as the primary learning management system for multiple users and institutions.
Security mitigations for this vulnerability involve implementing proper input validation and output encoding mechanisms throughout the application. The most effective solution is to upgrade to Moodle version 1.9.18 or later, which contains the necessary patches to address the XSS vulnerability. Additionally, administrators should implement Content Security Policy headers to limit script execution, ensure proper parameter sanitization in all user-input handling code, and conduct regular security audits of web applications. This vulnerability aligns with CWE-79, which specifically addresses Cross-Site Scripting flaws, and represents a common pattern that appears in many web applications where user input is not properly escaped or validated before being rendered in web pages. The ATT&CK framework categorizes this as a web application attack vector under the technique of code injection, specifically targeting the execution of malicious scripts within user contexts. Organizations should also consider implementing web application firewalls and regular security testing to identify similar vulnerabilities in other components of their educational technology infrastructure.