CVE-2025-46001: Simogeo Filemanager RCE Vulnerability

CVE-2025-46001 Overview

An arbitrary file upload vulnerability exists in the is_allowed_file_type() function of Simogeo Filemanager v2.3.0. This flaw allows unauthenticated remote attackers to bypass file type validation and upload malicious PHP files, resulting in arbitrary code execution on the target server. The vulnerability stems from improper input validation in the file upload handling mechanism, enabling attackers to gain full control of affected web applications.

Critical Impact

Unauthenticated attackers can achieve remote code execution by uploading crafted PHP files, potentially leading to complete server compromise, data theft, and lateral movement within the network.

Affected Products

• Simogeo Filemanager v2.3.0
• Earlier versions of Simogeo Filemanager may also be affected

Discovery Timeline

• 2025-07-18 - CVE-2025-46001 published to NVD
• 2025-10-14 - Last updated in NVD database

Technical Details for CVE-2025-46001

Vulnerability Analysis

This vulnerability is classified as CWE-434 (Unrestricted Upload of File with Dangerous Type). The is_allowed_file_type() function in Simogeo Filemanager fails to properly validate uploaded files, allowing attackers to bypass security controls designed to prevent dangerous file uploads. The network-accessible nature of this vulnerability means it can be exploited remotely without any authentication or user interaction required. Once a malicious PHP file is uploaded, the attacker can execute arbitrary commands on the underlying server with the privileges of the web server process.

Root Cause

The root cause lies in the flawed implementation of the is_allowed_file_type() function within Filemanager v2.3.0. The function does not adequately verify the true file type of uploaded content, likely relying on easily spoofed attributes such as file extensions or MIME types provided by the client. This insufficient validation allows attackers to disguise malicious PHP scripts as permitted file types and bypass the upload restrictions entirely.

Attack Vector

The attack vector is network-based, requiring no privileges or user interaction. An attacker can exploit this vulnerability by:

1. Crafting a malicious PHP file containing webshell code or other malicious payloads
2. Manipulating the file's metadata (extension, MIME type, or content headers) to bypass the is_allowed_file_type() validation
3. Uploading the crafted file through the Filemanager web interface
4. Accessing the uploaded PHP file directly via the web server to trigger code execution

The vulnerability manifests in the file upload validation logic within the is_allowed_file_type() function. Technical exploitation details are documented in the GitHub CVE-2025-46001 Document, and historical exploitation techniques for similar vulnerabilities in Filemanager can be found in Exploit-DB #38895.

Detection Methods for CVE-2025-46001

Indicators of Compromise

• Presence of unexpected PHP files in upload directories, particularly those with obfuscated content or webshell signatures
• Web server access logs showing requests to newly uploaded PHP files in Filemanager upload paths
• Anomalous outbound connections from the web server process
• Unexpected process execution or shell activity spawned by the web server user

Detection Strategies

• Monitor file upload directories for newly created PHP or other executable files
• Implement web application firewall (WAF) rules to detect file upload bypass attempts and malicious PHP content
• Deploy endpoint detection and response (EDR) solutions to identify post-exploitation behavior such as reverse shells or command execution
• Review web server logs for suspicious POST requests to Filemanager upload endpoints followed by GET requests to unusual file paths

Monitoring Recommendations

• Enable file integrity monitoring (FIM) on web-accessible directories to detect unauthorized file additions
• Configure SIEM alerts for patterns indicative of webshell deployment and access
• Monitor process creation events from web server processes (e.g., apache, nginx, php-fpm) for suspicious child processes

How to Mitigate CVE-2025-46001

Immediate Actions Required

• Remove or disable Simogeo Filemanager from production environments until a patched version is available
• Restrict network access to Filemanager installation directories using firewall rules or web server configuration
• Implement strict file upload validation at the application and infrastructure level, including server-side content inspection
• Audit upload directories for any existing malicious files that may have been uploaded

Patch Information

As of the last update, no official vendor patch has been announced for CVE-2025-46001. Organizations should monitor the GitHub Filemanager Repository for security updates. Until a patch is released, the recommended approach is to disable or remove the vulnerable component from production environments.

Workarounds

• Configure web server rules to prevent execution of PHP files in upload directories (e.g., using .htaccess or nginx location blocks)
• Implement a reverse proxy or WAF with rules to block file upload attempts containing PHP content
• Restrict access to Filemanager to trusted IP addresses or authenticated users only
• Deploy application-level controls to validate file content using magic bytes rather than relying on file extensions

# Example: Disable PHP execution in upload directory (Apache)
# Add to .htaccess in the upload directory
# php_flag engine off

# Example: Nginx configuration to block PHP execution in uploads
# location ~* /uploads/.*\.php$ {
#     deny all;
# }