CVE-2007-1235 in sitex
Summary
by MITRE
Unrestricted file upload vulnerability in sitex allows remote attackers to upload arbitrary PHP code via an avatar filename with a double extension such as .php.jpg, which fails verification and is saved as a .php file.
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Analysis
by VulDB Data Team • 08/25/2018
The vulnerability described in CVE-2007-1235 represents a critical security flaw in the sitex content management system that stems from inadequate input validation and file extension handling mechanisms. This unrestricted file upload vulnerability allows remote attackers to bypass security controls by exploiting a common weakness in web application file validation logic. The flaw specifically manifests when the system processes avatar uploads, where it fails to properly validate file extensions and content types, creating an avenue for malicious code execution.
The technical implementation of this vulnerability relies on a sophisticated attack vector that leverages the way file systems handle double extensions. When an attacker uploads a file named with a double extension such as .php.jpg, the system's validation process typically only examines the final extension and incorrectly assumes the file is safe because it ends with .jpg. However, the underlying file system or processing logic may save the file with its original extension, effectively creating a .php file that can be executed by the web server. This bypass mechanism operates through a fundamental flaw in the validation logic that fails to properly sanitize and verify the actual file content and its intended extension.
The operational impact of this vulnerability extends far beyond simple file upload functionality, creating a severe threat landscape for systems running affected versions of sitex. Attackers can leverage this flaw to execute arbitrary PHP code on the target server, potentially leading to complete system compromise, data theft, or server takeover. The vulnerability enables malicious actors to establish persistent backdoors, deploy web shells, or execute commands with the privileges of the web server process. This type of vulnerability directly maps to CWE-434, which specifically addresses "Unrestricted Upload of File with Dangerous Type" and represents a critical weakness in input validation and file handling processes. The attack pattern aligns with techniques documented in the ATT&CK framework under T1190 for "Exploit Public-Facing Application" and T1059 for "Command and Scripting Interpreter" where adversaries can execute code through uploaded malicious files.
Mitigation strategies for this vulnerability must address both the immediate security gap and implement comprehensive file validation controls. Organizations should implement strict file extension whitelisting mechanisms that reject any file with potentially dangerous extensions regardless of how they are named or what the system initially reports. The system must perform thorough content analysis of uploaded files rather than relying solely on extension checks, implementing MIME type validation and binary signature verification to ensure uploaded files match their claimed types. Additionally, uploaded files should be stored in a separate directory from executable code and should not be directly accessible through the web root. Security measures should include implementing proper file permissions, using randomized filenames during upload, and conducting regular security audits of file handling processes. The remediation approach should follow security best practices outlined in OWASP Top Ten and NIST guidelines for secure file upload implementations, ensuring that all file validation occurs at multiple levels within the application architecture to prevent similar bypass techniques from succeeding.