CVE-2007-4182 in WikiWebWeaver
Summary
by MITRE
Unrestricted file upload vulnerability in index.php in WikiWebWeaver 1.1 and earlier allows remote attackers to upload and execute arbitrary PHP code via an upload action specifying a filename with a double extension such as .gif.php, which is accessible from data/documents/.
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Analysis
by VulDB Data Team • 09/06/2018
The vulnerability described in CVE-2007-4182 represents a critical unrestricted file upload flaw within WikiWebWeaver version 1.1 and earlier systems. This vulnerability stems from inadequate input validation and sanitization mechanisms within the file upload functionality of the web application. The issue specifically manifests in the index.php script where users can upload files through an upload action that processes filenames without proper extension filtering or content verification. Attackers can exploit this weakness by crafting malicious filenames with double extensions such as .gif.php, which bypasses typical file type checks that might only examine the final extension. The vulnerability is particularly dangerous because it allows remote attackers to execute arbitrary PHP code on the target server, effectively granting them full control over the web application and potentially the underlying system.
The technical implementation of this vulnerability leverages the way web servers and applications process file uploads with multiple extensions. When a file is uploaded with a name like shell.gif.php, the web application may only check the final extension .php and allow the upload to proceed, while the web server interprets the file as a PHP script due to its executable nature. This occurs because many web applications perform only superficial validation on uploaded files, checking only the last extension rather than validating the actual file content or implementing comprehensive file type whitelisting. The uploaded files are stored in the data/documents/ directory, making them directly accessible via web requests, which allows attackers to execute their malicious code simply by requesting the uploaded file path. This flaw directly maps to CWE-434 which categorizes unrestricted file upload vulnerabilities as a serious security weakness that can lead to remote code execution.
The operational impact of this vulnerability extends far beyond simple code execution, as it provides attackers with complete system compromise capabilities. Once an attacker successfully uploads and executes malicious PHP code, they can perform various malicious activities including but not limited to data exfiltration, privilege escalation, backdoor installation, and further network reconnaissance. The vulnerability enables attackers to establish persistent access to the compromised system, potentially using the web application as a foothold for broader network infiltration. From an attack perspective, this vulnerability aligns with ATT&CK technique T1190 which describes the use of web shell deployment for maintaining access and executing commands on compromised systems. The impact is particularly severe for organizations relying on WikiWebWeaver as their content management platform, as it could lead to complete data breaches, service disruption, and potential regulatory compliance violations.
Mitigation strategies for CVE-2007-4182 require implementing comprehensive file upload validation and sanitization mechanisms. Organizations should implement strict file type validation that checks not only the file extension but also examines the actual file content using magic number verification or MIME type detection. The recommended approach includes maintaining a whitelist of allowed file extensions and implementing proper file naming conventions that prevent double extensions from being processed. Additionally, uploaded files should be stored outside the web root directory and should not be executable by the web server. The application should also implement proper access controls and file permissions, ensuring that uploaded files cannot be executed directly through web requests. Security measures should include regular security audits, input validation improvements, and ensuring that the web application is updated to a version that addresses this vulnerability. Organizations should also implement network-based detection mechanisms to monitor for suspicious file upload activities and establish incident response procedures to quickly address potential exploitation attempts. The vulnerability demonstrates the critical importance of defense in depth strategies where multiple security controls work together to prevent successful exploitation of file upload vulnerabilities.