CVE-2009-0291 in OpenX
Summary
by MITRE
Directory traversal vulnerability in fc.php in OpenX 2.6.3 allows remote attackers to include and execute arbitrary files via a .. (dot dot) in the MAX_type parameter.
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Analysis
by VulDB Data Team • 07/28/2025
The vulnerability identified as CVE-2009-0291 represents a critical directory traversal flaw within the OpenX advertising platform version 2.6.3. This security weakness resides in the fc.php script which processes the MAX_type parameter, creating an avenue for remote attackers to manipulate file inclusion mechanisms. The vulnerability stems from insufficient input validation and sanitization of user-supplied parameters, allowing malicious actors to exploit the system's file handling capabilities through crafted directory traversal sequences.
The technical implementation of this vulnerability involves the manipulation of the MAX_type parameter to include directory traversal sequences such as .. (dot dot) which enables attackers to navigate outside the intended directory boundaries. When the fc.php script processes these malformed parameters without proper validation, it inadvertently allows the inclusion of arbitrary files from the server's filesystem. This occurs because the application fails to properly sanitize or restrict the input before using it in file operations, creating a path traversal condition that can be exploited to access sensitive files or execute malicious code.
The operational impact of this vulnerability extends beyond simple file access, as it provides attackers with the capability to execute arbitrary code on the affected server. This represents a severe privilege escalation opportunity that could lead to complete system compromise, data exfiltration, or the installation of backdoors. The vulnerability affects the core functionality of OpenX's file inclusion mechanisms, potentially allowing attackers to access configuration files, database credentials, or other sensitive system information that could be leveraged for further attacks within the network infrastructure. The remote nature of this vulnerability means that attackers can exploit it without requiring local access or authentication, making it particularly dangerous for web applications.
Mitigation strategies for CVE-2009-0291 should focus on implementing proper input validation and sanitization measures that prevent directory traversal sequences from being processed. Organizations should apply the official security patches released by OpenX for version 2.6.3, which typically involve implementing proper parameter validation and restricting file access to predefined directories. The implementation of secure coding practices such as input filtering, output encoding, and proper file access controls aligns with established security frameworks including CWE-22 which specifically addresses directory traversal vulnerabilities. Additionally, network segmentation, web application firewalls, and regular security audits should be implemented to reduce the attack surface and provide defense-in-depth measures. The vulnerability also relates to ATT&CK technique T1059 which covers command and script injection, as successful exploitation could enable attackers to execute arbitrary commands on the compromised system.