CVE-2011-4807 in phpAlbum
Summary
by MITRE
Directory traversal vulnerability in main.php in phpAlbum 0.4.1.16 and earlier allows remote attackers to read arbitrary files via a .. (dot dot) in the var1 parameter.
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Analysis
by VulDB Data Team • 01/01/2025
The vulnerability identified as CVE-2011-4807 represents a critical directory traversal flaw within the phpAlbum 0.4.1.1.6 and earlier versions. This security weakness exists in the main.php script where user input is not properly sanitized before being processed. The vulnerability specifically manifests when the var1 parameter contains directory traversal sequences such as .. which allows attackers to navigate beyond the intended directory structure and access files that should remain restricted. This type of vulnerability falls under the Common Weakness Enumeration category CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw enables attackers to exploit the application's failure to validate user-supplied input, creating an opportunity to access sensitive files that may contain configuration data, user credentials, or other confidential information stored outside the web root directory.
The operational impact of this vulnerability extends beyond simple file access, as it can potentially allow attackers to retrieve critical system files, application source code, or database credentials that could lead to complete system compromise. When an attacker successfully exploits this vulnerability, they can navigate through the file system using the .. sequence to access files in parent directories, potentially reaching system configuration files, password files, or other sensitive data that should not be accessible through normal application operations. The attack vector is particularly dangerous because it requires minimal input manipulation and can be executed remotely without authentication, making it an attractive target for automated exploitation tools. This vulnerability aligns with ATT&CK technique T1083, which describes the discovery of system information through directory listing and file access techniques that adversaries use to understand system structure and identify valuable targets.
Mitigation strategies for CVE-2011-4807 require immediate implementation of input validation and sanitization measures within the affected phpAlbum application. The most effective approach involves implementing strict input validation that filters out or rejects any directory traversal sequences from user-supplied parameters before they are processed by the application. This can be achieved through regular expression filtering that removes or encodes potentially dangerous characters such as .., /, and \ from the var1 parameter. Additionally, developers should implement proper path normalization and validation that ensures all file operations occur within a predefined safe directory structure, preventing any navigation outside of intended boundaries. The application should also enforce proper access controls and implement the principle of least privilege, ensuring that file access operations are restricted to only necessary directories. System administrators should also consider implementing web application firewalls that can detect and block suspicious directory traversal patterns in real-time, providing an additional layer of protection against exploitation attempts. The vulnerability highlights the critical importance of input validation in web applications and serves as a reminder of the devastating consequences that can result from inadequate security controls in file handling operations.