CVE-2013-4753 in Claroline
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in Claroline 1.11.9 and earlier allow remote authenticated users to inject arbitrary web script or HTML via (1) the Search field in an inbox action to messaging/messagebox.php, (2) the "First name" field to auth/profile.php, or (3) the Speakers field in an rqAdd action to calendar/agenda.php.
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Analysis
by VulDB Data Team • 03/28/2019
The vulnerability described in CVE-2013-4753 represents a critical security flaw affecting Claroline versions 1.11.9 and earlier, specifically targeting cross-site scripting vulnerabilities that enable authenticated attackers to execute malicious code within the context of the victim's browser. This vulnerability exists due to inadequate input validation and output encoding mechanisms within the web application's core components, creating persistent security risks for users interacting with the platform's messaging, profile, and calendar functionalities. The vulnerability affects multiple attack vectors within the application's architecture, demonstrating a systemic weakness in the input sanitization process that could be exploited by malicious actors with legitimate user credentials.
The technical implementation of this vulnerability stems from the application's failure to properly sanitize user-supplied data before rendering it within web pages. In the messaging component, the Search field in the inbox action within messaging/messagebox.php does not adequately filter or encode user input, allowing attackers to inject malicious scripts that execute when other users view the inbox content. Similarly, the "First name" field in auth/profile.php lacks proper validation mechanisms, enabling attackers to submit malicious payloads that persist in user profiles and execute when profiles are displayed. The calendar component presents another vector through the Speakers field in the rqAdd action within calendar/agenda.php, where unfiltered input allows for script injection that can affect calendar event displays. These flaws align with CWE-79, which specifically addresses cross-site scripting vulnerabilities in web applications, and demonstrate the fundamental principle that all user-supplied input must be properly validated and sanitized before being processed or rendered.
The operational impact of these vulnerabilities extends beyond simple data corruption or display issues, as they provide attackers with persistent access to user sessions and potentially sensitive information within the Claroline environment. When authenticated users view pages containing malicious scripts injected through these vectors, the attacker's code executes within the user's browser context, potentially leading to session hijacking, credential theft, or further exploitation of the application's functionality. The attack requires only authenticated access, which significantly reduces the attack surface and makes these vulnerabilities particularly dangerous in environments where users maintain persistent access to educational or corporate platforms. The persistent nature of these vulnerabilities means that once injected, malicious payloads can affect multiple users over extended periods, creating a continuous threat vector that can be leveraged for data exfiltration or further compromise of the system.
Mitigation strategies for CVE-2013-4753 should focus on implementing comprehensive input validation and output encoding mechanisms across all user-facing application components. The primary remediation involves updating the affected Claroline versions to 1.11.10 or later, which contain the necessary patches addressing the input sanitization flaws. Additionally, administrators should implement proper content security policies that restrict script execution within the application's interface and ensure that all user-supplied data undergoes strict validation before being processed or displayed. The implementation of proper output encoding techniques, particularly for dynamic content generation, should be enforced across all application modules to prevent script injection attacks. Organizations should also consider implementing web application firewalls to provide additional protection layers and establish regular security auditing procedures to identify similar vulnerabilities in other components of their educational technology infrastructure. These measures align with ATT&CK technique T1059, which addresses execution of malicious code through web application vulnerabilities, and emphasize the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect against persistent threats in web-based educational platforms.