CVE-2011-3716 in Claroline
Summary
by MITRE
Claroline 1.9.7 allows remote attackers to obtain sensitive information via a direct request to a .php file, which reveals the installation path in an error message, as demonstrated by work/connector/linker.cnr.php and certain other files.
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Analysis
by VulDB Data Team • 02/10/2019
The vulnerability identified as CVE-2011-3716 affects Claroline version 1.9.7, a widely used open-source learning management system that facilitates online education and course management. This security flaw represents a classic information disclosure vulnerability that exposes sensitive system details to remote attackers without requiring authentication or privileged access. The vulnerability specifically manifests when attackers can directly access php files within the application's directory structure, particularly targeting files such as work/connector/linker.cnr.php and similar components. The flaw stems from the application's improper error handling mechanisms that fail to sanitize or suppress sensitive path information during error conditions, creating a direct pathway for attackers to discover the system's installation path through error messages.
From a technical perspective, this vulnerability operates as a path disclosure issue that falls under the Common Weakness Enumeration category CWE-200, which specifically addresses information exposure through improper error handling. The flaw occurs when the web application encounters an error condition while processing requests to specific php files, causing the system to output error messages that contain the full file system path where Claroline is installed. This type of information disclosure vulnerability is particularly dangerous because it provides attackers with critical system topology information that can be leveraged in subsequent attack phases. The vulnerability demonstrates poor input validation and error handling practices within the application's codebase, where error messages are generated without proper sanitization of system paths or file locations.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a foundation for more sophisticated attacks within the attack chain defined by the MITRE ATT&CK framework. When attackers obtain the installation path, they gain valuable reconnaissance information that can be used to map the application's directory structure, identify potential attack vectors, and plan more targeted exploitation attempts. The vulnerability affects the confidentiality aspect of the CIA triad by exposing sensitive system information that should remain private to authorized personnel only. Additionally, this flaw can contribute to privilege escalation attempts or other attacks that rely on detailed knowledge of the system's file structure and deployment environment.
The exploitation of this vulnerability requires minimal technical expertise and can be accomplished through simple web requests to specific php files within the Claroline installation. Attackers need only construct a URL pointing to vulnerable files and observe the error messages to extract the installation path. This characteristic makes the vulnerability particularly dangerous as it can be discovered and exploited by automated scanning tools or less experienced attackers. Organizations running vulnerable versions of Claroline face significant risk of information disclosure that could expose their system architecture and potentially enable more advanced attacks such as directory traversal or remote code execution attempts. The vulnerability also impacts the application's overall security posture by providing attackers with insights into the system's deployment configuration and file organization.
Mitigation strategies for CVE-2011-3716 should focus on implementing proper error handling and input validation mechanisms throughout the Claroline application. The primary remediation involves configuring the web server and application to suppress detailed error messages that reveal system paths, typically through php configuration settings or application-level error handling modifications. Organizations should also implement proper access controls that prevent direct access to internal php files through web requests, utilizing directory permissions and web server configuration to restrict access to sensitive components. Additionally, upgrading to a patched version of Claroline that addresses this vulnerability is essential, as the issue represents a known security flaw that has been resolved in subsequent releases. Security monitoring should include scanning for exposed system paths and error messages that could indicate similar vulnerabilities in other applications within the organization's infrastructure.