CVE-2009-0290 in GNUBoard
Summary
by MITRE
Directory traversal vulnerability in common.php in SIR GNUBoard 4.31.03 allows remote attackers to include and execute arbitrary local files via a .. (dot dot) in the g4_path parameter. NOTE: in some environments, this can be leveraged for remote code execution via a data: URI or a UNC share pathname.
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Analysis
by VulDB Data Team • 11/22/2024
The vulnerability identified as CVE-2009-0290 represents a critical directory traversal flaw within the SIR GNUBoard 4.31.03 content management system. This weakness resides in the common.php file where the g4_path parameter fails to properly validate or sanitize user input, creating an opportunity for attackers to manipulate file inclusion mechanisms. The vulnerability stems from inadequate input validation that allows malicious actors to exploit the path traversal technique using the .. (dot dot) sequence, which is a well-established method for navigating upward through directory structures in file systems.
The technical implementation of this flaw enables remote attackers to include and execute arbitrary local files on the target system by manipulating the g4_path parameter. When the application processes this parameter without proper sanitization, it becomes possible for an attacker to construct malicious paths that bypass normal file access controls. This vulnerability operates at the application layer and specifically targets the file inclusion functionality that is fundamental to many web applications. The issue is classified under CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The vulnerability's exploitation potential is significantly enhanced in environments where additional attack vectors exist, such as when data: URIs or UNC share pathnames can be leveraged to achieve remote code execution.
The operational impact of this vulnerability extends beyond simple file inclusion, as it can be weaponized for complete system compromise in suitable environments. Attackers can utilize this weakness to access sensitive system files, configuration data, or even execute malicious code remotely. The remote code execution capability through data: URI or UNC share pathnames transforms this directory traversal vulnerability into a more severe threat, potentially allowing attackers to establish persistent access, escalate privileges, or deploy additional malware. The vulnerability affects the integrity and confidentiality of the affected system, as unauthorized parties can gain access to critical information and potentially take control of the web server. This type of vulnerability aligns with ATT&CK technique T1059 which describes the execution of commands through various methods including file inclusion attacks.
The remediation of this vulnerability requires immediate implementation of proper input validation and sanitization measures within the application code. Developers must ensure that all user-supplied input, particularly parameters used in file operations, undergo thorough validation to prevent directory traversal attempts. The solution involves implementing strict path validation that rejects or normalizes input containing sequences such as .. or \. Organizations should also implement proper access controls and file system permissions to limit the damage that can be caused by successful exploitation. Regular security audits and code reviews should be conducted to identify similar vulnerabilities in other applications, as path traversal issues remain common in web applications. Additionally, the use of secure coding practices and input validation libraries can help prevent such vulnerabilities from being introduced during the development phase, which aligns with the security controls recommended in various cybersecurity frameworks including NIST SP 800-53 and ISO 27001 standards.