CVE-2007-3517 in Claroline
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in Claroline 1.8.3 allow remote attackers to inject arbitrary web script or HTML via the PATH_INFO (PHP_SELF) to (1) index.php, (2) demo/claroline170/index.php, and possibly other scripts.
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Analysis
by VulDB Data Team • 07/06/2025
The vulnerability described in CVE-2007-3517 represents a critical cross-site scripting flaw affecting Claroline 1.8.3, a widely used learning management system. This vulnerability stems from inadequate input validation and sanitization mechanisms within the application's handling of HTTP request parameters. The specific weakness occurs when the application processes the PATH_INFO variable, which is derived from PHP_SELF, without properly escaping or filtering user-supplied data before incorporating it into web responses. This flaw allows malicious actors to inject arbitrary HTML and JavaScript code through carefully crafted URLs that manipulate the PATH_INFO parameter.
The technical implementation of this vulnerability aligns with CWE-79, which specifically addresses cross-site scripting vulnerabilities in web applications. The flaw operates by exploiting the application's failure to sanitize user input that flows directly into HTTP responses, creating a persistent vector for malicious code execution. Attackers can construct specially crafted URLs that, when visited by unsuspecting users, execute malicious scripts within the context of the victim's browser session. The vulnerability affects multiple entry points including index.php and demo/claroline170/index.php, suggesting a systemic issue in the application's input handling mechanisms rather than isolated code defects. This widespread impact indicates that the core vulnerability exists in the application's foundational request processing logic rather than in individual scripts.
From an operational perspective, this vulnerability poses significant risks to educational institutions relying on Claroline for their learning management needs. Successful exploitation could enable attackers to steal user credentials, hijack sessions, deface educational portals, or redirect users to malicious sites. The remote nature of the attack means that threat actors can exploit this vulnerability without requiring physical access to the system or knowledge of internal network structures. The impact extends beyond simple data theft to potentially compromising the entire educational platform, as the injected scripts could manipulate course content, user permissions, or administrative functions. Users who visit compromised pages could unknowingly execute malicious code that persists in their browser sessions, creating ongoing security risks.
The attack surface for this vulnerability includes any user who visits a maliciously crafted URL containing the XSS payload, making it particularly dangerous in environments where users frequently click on links or navigate through multiple web applications. The vulnerability's persistence in multiple scripts suggests that defenders should consider the entire application architecture when implementing defensive measures. Organizations should implement comprehensive input validation and output encoding mechanisms to prevent similar issues in the future. The recommended mitigations include implementing strict input sanitization for all PATH_INFO and similar variables, deploying web application firewalls to detect and block malicious payloads, and ensuring that all user-supplied data is properly escaped before being rendered in web responses. Additionally, regular security audits and penetration testing should be conducted to identify and remediate similar vulnerabilities in other web applications within the organization's infrastructure, aligning with the defensive strategies outlined in the ATT&CK framework's web application exploitation techniques.