CVE-2008-2833 in le.cms
Summary
by MITRE
admin/upload.php in le.cms 1.4 and earlier allows remote attackers to bypass administrative authentication, and upload and execute arbitrary files in images/, via a nonzero value for the submit0 parameter in conjunction with filenames in the filename and upload parameters.
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Analysis
by VulDB Data Team • 10/29/2024
The vulnerability described in CVE-2008-2833 represents a critical authentication bypass flaw in le.cms version 1.4 and earlier systems. This issue resides within the admin/upload.php component which serves as an administrative file upload interface. The vulnerability stems from inadequate input validation and authentication checks that allow malicious actors to circumvent the standard administrative access controls. Attackers can exploit this weakness by manipulating specific parameters in the upload request to gain unauthorized access to the administrative functions of the content management system.
The technical exploitation mechanism involves the manipulation of the submit0 parameter to a nonzero value while simultaneously providing crafted filenames through the filename and upload parameters. This combination allows attackers to bypass the authentication layer that should normally restrict access to administrative upload functionality. The vulnerability specifically targets the file upload process in the images/ directory, which serves as the target location for malicious file uploads. The flaw demonstrates poor input sanitization where the system fails to properly validate user-supplied data before processing upload requests, creating a path for arbitrary code execution through file upload mechanisms.
This vulnerability has significant operational impact as it provides attackers with complete administrative control over the affected system. Once authenticated, malicious actors can upload malicious files to the images/ directory and subsequently execute them within the web application context. The implications extend beyond simple unauthorized access to include potential system compromise, data exfiltration, and service disruption. The vulnerability affects the integrity and confidentiality of the entire content management system, as attackers can modify or delete content, access sensitive information, and potentially establish persistent access through uploaded backdoors or malicious scripts. This type of vulnerability directly violates security principles of least privilege and proper authentication enforcement.
The vulnerability maps to CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-434 (Unrestricted Upload of File with Dangerous Type) within the CWE taxonomy, indicating weaknesses in path validation and file type restriction controls. From an ATT&CK framework perspective, this vulnerability aligns with T1078 (Valid Accounts) and T1505.003 (Server Software Component) techniques, as it enables attackers to leverage administrative privileges and exploit server-side components. The attack surface is particularly concerning because it combines authentication bypass with remote code execution capabilities, providing attackers with a complete attack chain from initial access through system compromise.
Mitigation strategies should focus on immediate patching of the affected le.cms versions to address the authentication bypass and file upload validation issues. Implementing proper input validation and sanitization measures is essential to prevent parameter manipulation attacks. The system should enforce strict file type validation and reject uploads of executable files or scripts. Access controls should be reinforced through proper authentication mechanisms and session management. Network-level protections including web application firewalls and intrusion detection systems can help detect and block exploitation attempts. Regular security audits and code reviews should be conducted to identify similar vulnerabilities in other components of the system. Additionally, implementing principle of least privilege access controls and monitoring upload activities can provide early detection of unauthorized access attempts.