CVE-2006-6625 in Moodle
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in mod/forum/discuss.php in Moodle 1.6.1 allows remote attackers to inject arbitrary web script or HTML via the navtail parameter. NOTE: The provenance of this information is unknown; the details are obtained solely from third party information.
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Analysis
by VulDB Data Team • 08/10/2018
This cross-site scripting vulnerability exists within the Moodle learning management system version 1.6.1, specifically in the mod/forum/discuss.php component. The flaw allows remote attackers to execute malicious web scripts or HTML code through manipulation of the navtail parameter, representing a classic persistent XSS attack vector that can compromise user sessions and data integrity. The vulnerability stems from inadequate input validation and output sanitization mechanisms within the forum discussion page implementation.
The technical exploitation of this vulnerability occurs when user-supplied input from the navtail parameter is directly incorporated into the web page response without proper sanitization or encoding. This creates an environment where malicious actors can inject script tags, javascript payloads, or other malicious HTML content that executes in the context of other users' browsers. The attack typically involves crafting a malicious URL containing the XSS payload in the navtail parameter, which when visited by an unsuspecting user triggers the execution of the injected code. This represents a CWE-79 vulnerability classification, specifically categorized under "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", which is a fundamental web application security weakness that has been consistently identified as one of the most prevalent security risks.
The operational impact of this vulnerability extends beyond simple script execution, as it can lead to session hijacking, credential theft, data exfiltration, and potentially full system compromise. Attackers could exploit this vulnerability to steal user authentication tokens, access sensitive course materials, manipulate forum content, or redirect users to malicious websites. The attack surface is particularly concerning in educational environments where Moodle platforms host thousands of users, making the potential impact of such an XSS vulnerability significant for institutional security. This vulnerability can be categorized under the ATT&CK technique T1059.007 for "Command and Scripting Interpreter: JavaScript' and T1566.001 for 'Phishing: Spearphishing Attachment' when considering the broader attack chain that could leverage this weakness.
Organizations utilizing Moodle 1.6.1 should immediately implement mitigations including input validation and output encoding for all user-supplied parameters, particularly those used in web page generation contexts. The most effective immediate solution involves implementing proper HTML escaping for all output generated from user input, specifically ensuring that the navtail parameter and similar parameters are sanitized before inclusion in web responses. Additionally, implementing Content Security Policy headers can provide an additional layer of protection against XSS attacks by restricting script execution. The vulnerability highlights the critical importance of input validation and output encoding practices as outlined in OWASP Top 10 and the Secure Coding guidelines that should be applied consistently across all web application components. System administrators should also consider implementing web application firewalls and monitoring for suspicious parameter values to detect potential exploitation attempts.