CVE-2007-0871 in eXtreme File Hosting
Summary
by MITRE
Unrestricted file upload vulnerability in eXtremePow eXtreme File Hosting allows remote attackers to upload arbitrary PHP code via a filename with a double extension such as (1) .rar.php or (2) .zip.php.
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Analysis
by VulDB Data Team • 08/23/2025
The vulnerability identified as CVE-2007-0871 represents a critical unrestricted file upload flaw within the eXtremePow eXtreme File Hosting platform that exposes systems to remote code execution risks. This vulnerability stems from inadequate input validation and sanitization mechanisms that fail to properly inspect file extensions and content, allowing malicious actors to bypass security measures through strategic filename manipulation techniques.
The technical exploitation of this vulnerability relies on the manipulation of file extensions through double extension attacks where attackers can append additional extensions to filenames to circumvent upload restrictions. Specifically the vulnerability allows attackers to upload files with extensions such as .rar.php or .zip.php, which can be executed as PHP code on the server. This technique exploits the fact that many web applications perform extension checks but fail to validate the actual content or process the file in a secure manner. The vulnerability is classified under CWE-434 Unrestricted Upload of File with Dangerous Type, which is a well-documented weakness in web application security where applications allow users to upload files without proper validation of file types or content.
The operational impact of this vulnerability is severe as it provides remote attackers with the capability to execute arbitrary code on the target system, potentially leading to complete system compromise. An attacker could upload a malicious PHP script that would be executed by the web server, allowing for remote command execution, data exfiltration, system enumeration, and further network infiltration. This vulnerability directly maps to ATT&CK technique T1190 Exploit Public-Facing Application, where adversaries leverage vulnerabilities in publicly accessible web applications to establish persistent access. The threat actor could gain unauthorized access to the server, potentially using the compromised system as a foothold for further attacks within the network infrastructure.
The root cause of this vulnerability lies in the application's insufficient validation of uploaded files, where the system fails to properly verify file content or enforce strict file type restrictions. This flaw allows attackers to upload files that appear to be benign archive formats but contain malicious PHP code that executes when the file is accessed or processed by the web server. The vulnerability demonstrates poor input validation practices and highlights the importance of implementing comprehensive file upload security measures that go beyond simple extension checking.
Mitigation strategies for this vulnerability should include implementing strict file type validation, enforcing content-based checks rather than relying solely on file extensions, and implementing proper file handling mechanisms that prevent execution of uploaded files. Organizations should deploy web application firewalls to detect and block suspicious upload patterns, implement proper file naming conventions that prevent double extensions, and ensure that uploaded files are stored outside the web root directory. Additionally, regular security audits and penetration testing should be conducted to identify and remediate similar vulnerabilities in web applications. The vulnerability underscores the critical importance of following secure coding practices as outlined in OWASP Top Ten and other industry security standards to prevent such dangerous flaws from being introduced into web applications.