CVE-2011-3780 in PHP iCalendar
Summary
by MITRE
PHP iCalendar 2.4 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 rss/rss_common.php and certain other files.
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Analysis
by VulDB Data Team • 01/22/2018
The vulnerability identified as CVE-2011-3780 affects PHP iCalendar version 2.4 and represents a classic information disclosure flaw that exposes sensitive system details to remote attackers. This vulnerability resides in the application's error handling mechanism where direct requests to specific php files trigger error messages containing the absolute installation path of the vulnerable system. The issue manifests when attackers make direct requests to files such as rss/rss_common.php and other related components within the application's directory structure.
The technical exploitation of this vulnerability follows a straightforward pattern where an attacker crafts a request directly to a php file within the application's codebase without proper authentication or authorization. When the application processes this request and encounters an error condition, it inadvertently reveals the full file system path through error messages. This occurs because the php application lacks proper error handling or sanitization of error messages before they are returned to the client. The vulnerability is classified under CWE-200, which specifically addresses information exposure, and represents a fundamental security misconfiguration that violates the principle of least privilege.
The operational impact of this vulnerability extends beyond simple path disclosure, as the exposed installation paths provide attackers with crucial reconnaissance information for subsequent attacks. Knowledge of the exact file system structure enables attackers to plan more sophisticated exploitation techniques, potentially leading to further information disclosure, local file inclusion vulnerabilities, or even remote code execution if other weaknesses exist within the application. The vulnerability affects the confidentiality aspect of the CIA triad by leaking system information that should remain private and protected from unauthorized access. Attackers can leverage this information to map the application's architecture and identify potential attack vectors within the system's file structure.
Mitigation strategies for CVE-2011-3780 involve implementing proper error handling mechanisms that prevent sensitive information from being exposed to end users or external parties. Organizations should configure their php applications to suppress detailed error messages in production environments and instead display generic error pages that do not reveal system paths or internal application details. The implementation of proper logging mechanisms should be established to capture error conditions without exposing them to the client. Additionally, access controls should be enforced to prevent direct access to php files that are not intended for public consumption. This vulnerability aligns with ATT&CK technique T1212, which covers exploitation for credential access through information disclosure, and emphasizes the importance of proper input validation and error handling as outlined in the OWASP Top Ten. The remediation process requires updating the application to a patched version or implementing custom error handling that prevents path disclosure while maintaining application functionality. Security configurations should also include disabling directory listing and ensuring that error reporting is appropriately configured to avoid exposing system information to unauthorized users.