CVE-2008-7209 in OneCMS
Summary
by MITRE
Unrestricted file upload vulnerability in the add2 action in a_upload.php in OneCMS 2.4, and possibly earlier, allows remote attackers to execute arbitrary code by uploading a file with an executable extension and using a safe content type such as image/gif, then accessing it via a direct request to the file in an unspecified directory.
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Analysis
by VulDB Data Team • 10/13/2024
The vulnerability described in CVE-2008-7209 represents a critical unrestricted file upload flaw in OneCMS 2.4 and potentially earlier versions. This weakness resides within the add2 action of the a_upload.php component, where the application fails to properly validate file extensions and content types before processing uploads. The vulnerability stems from inadequate input sanitization mechanisms that permit attackers to bypass security controls designed to prevent execution of malicious files. The flaw specifically allows remote attackers to upload files with executable extensions such as .php, .asp, or .jsp while disguising them with seemingly benign content types like image/gif, which are typically considered safe for web applications.
From a technical perspective, this vulnerability operates through a combination of insufficient file type validation and content type manipulation. When an attacker uploads a file with an executable extension but a safe MIME type such as image/gif, the application's upload handler accepts the file without proper verification of its actual content or intended execution context. The system's lack of proper file extension checking and content type validation creates an exploitable condition where malicious code can be stored on the server and executed through direct access requests. The unspecified directory mentioned in the vulnerability description suggests that the uploaded files may be placed in a location that allows direct web access, enabling immediate execution of the malicious payload.
The operational impact of this vulnerability is severe and multifaceted. An attacker who successfully exploits this flaw can achieve arbitrary code execution on the target server, potentially leading to complete system compromise. This allows for unauthorized access to sensitive data, privilege escalation, and the establishment of persistent backdoors. The vulnerability can be exploited remotely without requiring authentication, making it particularly dangerous as it can be leveraged by attackers from anywhere on the internet. The implications extend beyond simple code execution to include potential data exfiltration, system reconnaissance, and the ability to use the compromised server as a launch point for further attacks against other systems within the network infrastructure.
Security professionals should address this vulnerability through multiple mitigation strategies aligned with established frameworks such as the CWE (Common Weakness Enumeration) classification system which categorizes this as a weakness in input validation and file handling. The ATT&CK framework would classify this vulnerability under the T1190 technique for "Exploit Public-Facing Application" and potentially T1059 for "Command and Scripting Interpreter" as attackers would execute commands through the uploaded malicious files. Organizations should implement comprehensive file upload validation controls including strict extension whitelisting, content type verification, and proper file storage separation from web-accessible directories. Additionally, regular security audits, input sanitization, and the principle of least privilege should be enforced to minimize the attack surface and prevent similar vulnerabilities from being introduced in future implementations.
The vulnerability demonstrates the critical importance of proper file upload validation in web applications and highlights how seemingly minor implementation flaws can lead to complete system compromise. This particular weakness underscores the necessity of defense-in-depth strategies and the importance of not relying solely on client-side validation or simple content type checks. Organizations should prioritize regular vulnerability assessments and maintain up-to-date security patches to prevent exploitation of known vulnerabilities like CVE-2008-7209. The incident serves as a reminder that secure coding practices, including thorough input validation and proper file handling procedures, are essential components of robust application security architectures.