CVE-2005-2813 in FlatNuke
Summary
by MITRE
Directory traversal vulnerability in FlatNuke 2.5.6 and possibly earlier allows remote attackers to read arbitrary files via ".." sequences and "%00" (trailing null byte) characters in the id parameter to the read mod in index.php.
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Analysis
by VulDB Data Team • 07/06/2025
The vulnerability identified as CVE-2005-2813 represents a critical directory traversal flaw within FlatNuke 2.5.6 and potentially earlier versions of this content management system. This security weakness resides in the read module functionality of the index.php file, where user input containing specific malicious sequences can be exploited to access files outside the intended directory structure. The vulnerability operates through a combination of directory traversal techniques that leverage both standard parent directory references and null byte injection methods to bypass normal file access controls.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the FlatNuke application's file handling mechanisms. When the id parameter in the read module receives input containing ".." sequences, the application fails to properly sanitize these path traversal characters, allowing attackers to navigate upward through the directory hierarchy. The addition of "%00" trailing null byte characters further amplifies this exploit by potentially terminating string processing routines, enabling attackers to bypass certain security checks that might otherwise prevent access to restricted files. This combination creates a powerful attack vector that can be leveraged to read arbitrary files from the server's file system.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to access sensitive system files, configuration data, and potentially user credentials stored within the application's directory structure. Attackers can exploit this weakness to retrieve database connection details, administrative login information, and other critical system components that could lead to full system compromise. The vulnerability's remote nature means that exploitation does not require local system access, making it particularly dangerous as it can be leveraged from any network location to target vulnerable installations. This type of vulnerability falls under CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and sanitization measures within the FlatNuke application. The recommended approach involves filtering out or escaping special characters such as ".." sequences and null bytes from user input before processing. Additionally, implementing proper access controls and ensuring that the application runs with minimal required privileges can significantly reduce the impact of successful exploitation attempts. Organizations should also consider implementing web application firewalls that can detect and block malicious path traversal patterns, particularly those involving null byte sequences. The ATT&CK framework categorizes this type of vulnerability under T1083 - File and Directory Discovery, highlighting the reconnaissance phase that attackers typically conduct before executing more sophisticated attacks. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities in legacy applications, as many older systems continue to operate without proper security updates or patches.