CVE-2006-4784 in Moodle
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in Moodle 1.6.1 and earlier might allow remote attackers to inject arbitrary web script or HTML via unspecified parameters to (1) doc/index.php or (2) files/index.php.
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Analysis
by VulDB Data Team • 07/08/2019
The vulnerability identified as CVE-2006-4784 represents a critical cross-site scripting weakness affecting Moodle versions 1.6.1 and earlier. This security flaw resides in the web application's input validation mechanisms and specifically targets two key files within the Moodle platform's documentation and file management systems. The vulnerability stems from inadequate sanitization of user-supplied input parameters that are processed by the doc/index.php and files/index.php scripts, creating exploitable entry points for malicious actors to inject harmful web scripts or HTML content.
The technical implementation of this vulnerability aligns with CWE-79, which categorizes cross-site scripting flaws as weaknesses in input validation where untrusted data is improperly handled and reflected back to users without adequate sanitization. Attackers can leverage this vulnerability by crafting malicious payloads that target the unspecified parameters within the affected PHP scripts, allowing them to execute arbitrary code in the context of a victim's browser session. The flaw operates at the application layer where user input flows directly into web responses without proper encoding or validation, creating persistent XSS attack vectors.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform session hijacking, steal sensitive user credentials, manipulate course content, or redirect users to malicious websites. In educational environments where Moodle serves as a central learning management system, this vulnerability could compromise the integrity of entire academic platforms, affecting thousands of users including students, instructors, and administrators. The remote nature of the attack means that exploitation can occur from any location without requiring physical access to the system, making it particularly dangerous for widespread deployment.
Organizations utilizing affected Moodle versions should implement immediate mitigations including input validation and output encoding for all user-supplied parameters, proper sanitization of HTML content before rendering, and deployment of web application firewalls to detect and block malicious payloads. The vulnerability demonstrates the critical importance of maintaining up-to-date software versions, as Moodle 1.6.1 and earlier versions contained multiple security flaws that were subsequently addressed in patch releases. System administrators should also consider implementing CSP (Content Security Policy) headers to provide additional protection against XSS attacks, and establish regular security audits to identify similar vulnerabilities in other web applications within the educational infrastructure. This vulnerability serves as a reminder of the ongoing need for robust security practices in web application development and the importance of adhering to secure coding standards that prevent injection attacks through proper input validation and output encoding mechanisms.