CVE-2011-3706 in ATutor
Summary
by MITRE
ATutor 2.0 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 users/tool_settings.inc.php and certain other files.
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Analysis
by VulDB Data Team • 02/10/2019
The vulnerability identified as CVE-2011-3706 affects ATutor version 2.0, a widely used open-source learning management system that provides educational institutions with tools for creating and managing online courses. This security flaw represents a classic information disclosure vulnerability that exposes critical system details to unauthorized parties. The vulnerability stems from the application's inadequate error handling mechanisms, which fail to sanitize or mask sensitive information during error conditions. When remote attackers make direct requests to specific php files within the application's directory structure, the system responds with detailed error messages that inadvertently reveal the complete installation path of the ATutor system.
The technical implementation of this vulnerability occurs through the application's failure to properly validate and sanitize input parameters when processing requests for php files. Specifically, when attackers target files such as users/tool_settings.inc.php and similar components, the system generates error responses that contain the full server path where ATutor is installed. This path disclosure represents a significant security risk as it provides attackers with precise information about the target system's file structure and deployment environment. The vulnerability is particularly dangerous because it operates without requiring authentication or specific privileges, making it accessible to any remote attacker who can access the web application.
The operational impact of this vulnerability extends beyond simple path disclosure, as it creates a foundation for more sophisticated attacks. Attackers who obtain the installation path can use this information to plan targeted exploitation attempts, including directory traversal attacks, privilege escalation, or further reconnaissance activities. The disclosed path information enables attackers to understand the application's directory structure, potentially identifying other vulnerable components or configuration files that may exist within the same installation. This vulnerability aligns with CWE-200, which categorizes information exposure flaws, and demonstrates how seemingly minor error handling deficiencies can create significant security implications. From an attacker's perspective, this information disclosure provides the initial reconnaissance data necessary for more advanced exploitation techniques.
Mitigation strategies for CVE-2011-3706 require immediate implementation of proper error handling and input validation measures. Organizations should configure their web applications to suppress detailed error messages and replace them with generic responses that do not reveal system paths or internal structures. The recommended approach includes implementing custom error pages that do not expose server information, configuring web server settings to prevent direct access to sensitive php files, and ensuring that error logging occurs on the server side without exposing details to end users. Security professionals should also consider implementing web application firewalls that can detect and block direct requests to php files that may trigger path disclosure errors. Additionally, regular security audits should verify that all error handling mechanisms properly sanitize output and that no sensitive information is exposed through error messages, aligning with ATT&CK technique T1212 which addresses exploitation of information disclosure vulnerabilities. The remediation process must also include updating the ATutor installation to a patched version that addresses this specific flaw, as the vulnerability was introduced due to poor coding practices in the application's error handling implementation.