Overview
This article provides an in-depth analysis of CVE-2025-63994, a critical arbitrary file upload vulnerability affecting RichFilemanager version 2.7.6. This vulnerability allows unauthenticated attackers to upload malicious files to the server, potentially leading to remote code execution (RCE).
Technical Details
CVE-2025-63994 stems from insufficient input validation in the /php/UploadHandler.php component of RichFilemanager. The vulnerability allows an attacker to bypass intended file type restrictions by crafting a malicious file and uploading it via the file upload functionality. Specifically, the application does not properly sanitize uploaded file names and contents. This enables the injection of executable code within a file that the server interprets as executable upon access.
An attacker could, for example, upload a PHP file containing malicious code that, when accessed through a web browser, would execute commands on the server with the privileges of the web server user. This could lead to complete system compromise.
CVSS Analysis
As of the publication of this article, a CVSS score is currently listed as N/A. However, given the nature of the vulnerability and the potential for remote code execution, it would likely receive a high CVSS score if calculated, potentially between 8.8 (High) and 10.0 (Critical) depending on exploitability metrics and scope.
Possible Impact
The successful exploitation of CVE-2025-63994 can have severe consequences, including:
- Remote Code Execution (RCE): Attackers can execute arbitrary code on the server, potentially gaining full control.
- Data Breach: Sensitive data stored on the server could be compromised.
- Website Defacement: The attacker could modify website content to spread malware or display malicious messages.
- Denial of Service (DoS): The attacker could crash the server, rendering the website unavailable.
- Lateral Movement: An attacker can potentially use the compromised server as a launching point to attack other systems on the network.
Mitigation and Patch Steps
To mitigate the risk of CVE-2025-63994, the following steps are recommended:
- Upgrade RichFilemanager: Check the RichFilemanager GitHub repository for a patched version (later than 2.7.6) and upgrade immediately.
- Implement Strict File Type Validation: Enforce strong file type validation on the server-side, going beyond client-side checks. Reject file types that are not explicitly allowed.
- Sanitize File Names: Thoroughly sanitize uploaded file names to remove any potentially malicious characters or code.
- Restrict File Upload Directory Permissions: Configure the file upload directory with the minimum necessary permissions to prevent execution of uploaded files. Ensure that the web server user does not have write or execute permissions to the uploaded file directory.
- Web Application Firewall (WAF): Deploy a WAF with rules to detect and block malicious file upload attempts.
- Regular Security Audits: Conduct regular security audits of your web applications to identify and address potential vulnerabilities.
