CVE-2025-32028
Remediation / Mitigation Strategy: CVE-2025-32028 - HAX CMS PHP Unrestricted File Upload
Description of Vulnerability:
HAX CMS PHP utilizes a flawed denylist approach to restrict file uploads. The HAXCMSFile.php save function blocks .php, .sh, .js, and .css file extensions, but this list is incomplete. Attackers can bypass this restriction by uploading files with different extensions that can be interpreted as executable by the web server (e.g., .php5, .phtml, .htaccess, or SVG files with embedded scripts). This allows for arbitrary code execution on the server.
Severity:
Critical. The vulnerability has a CVSS score of 9.9. Unrestricted file upload can lead to complete system compromise, including data theft, server takeover, and denial of service.
Known Exploit:
Attackers can upload malicious files disguised with different extensions or other techniques to bypass the denylist. Once uploaded, these files can be executed, allowing them to execute arbitrary code on the server with the permissions of the web server user. This can include:
- Uploading a web shell for persistent access.
- Modifying website content.
- Stealing sensitive data from the database or file system.
- Escalating privileges.
- Launching attacks against other systems on the network.
Remediation:
- Upgrade: Upgrade HAX CMS PHP to version 10.0.3 or later. This version contains a fix for the vulnerability. This is the primary and most effective solution.
Mitigation (If immediate upgrade is not possible):
If an immediate upgrade is not possible, implement the following mitigations. These mitigations are less effective than upgrading and should be considered temporary measures.
Implement a comprehensive allowlist: Replace the denylist with an allowlist of allowed file types. Only permit file extensions that are absolutely necessary for the application’s functionality. For example,
.jpg,.png,.giffor images. All other file types should be rejected.Validate file content: Regardless of the file extension, perform server-side validation of the file’s content. Use techniques like:
- Magic number verification: Check the file’s header (magic number) to ensure it matches the expected file type.
- Content scanning: Use antivirus or other content scanning tools to detect malicious code within uploaded files.
Restrict file upload location: Store uploaded files in a directory outside the web server’s document root. This prevents direct execution of the files via HTTP requests. If files need to be served, use a separate, dedicated script to serve the files in a safe manner (e.g., setting appropriate content-type headers and preventing script execution).
Enforce strict file permissions: Ensure that uploaded files have limited permissions. Prevent the web server user from executing the uploaded files (e.g., set permissions to 644 or similar).
Web Application Firewall (WAF) rules: Implement WAF rules to detect and block malicious file uploads. Create rules to block file uploads with suspicious extensions, content, or patterns.
Monitor file uploads: Implement monitoring to detect suspicious file uploads. Log file uploads and alert on unusual file extensions, sizes, or content.
Disable PHP execution in the upload directory: Configure the web server to prevent PHP execution in the upload directory. This can be done using
.htaccessfiles (if Apache is used) or other server configuration directives. Example.htaccesscode:
<Files *>
mod_php7.c to your PHP module version if necessary).
Testing:
After applying the remediation or mitigations, thoroughly test the file upload functionality to ensure that malicious files cannot be uploaded or executed. Try to bypass the defenses using different file extensions, content manipulation techniques, and other known attack vectors.
Note: All mitigation steps are less secure than upgrading to the patched version. Apply remediation step as soon as feasible.
Assigner
- GitHub, Inc. [email protected]
Date
- Published Date: 2025-04-08 16:15:28
- Updated Date: 2025-04-08 20:15:28