CVE-2025-40625: Tcman Gim RCE Vulnerability

CVE-2025-40625 Overview

CVE-2025-40625 is an unrestricted file upload vulnerability in TCMAN's GIM version 11. This critical vulnerability allows an unauthenticated attacker to upload arbitrary files to the server, including malicious files that can be leveraged to achieve Remote Code Execution (RCE). The vulnerability stems from inadequate validation of uploaded file types and content, enabling attackers to bypass security controls without any prior authentication.

Critical Impact

Unauthenticated attackers can upload malicious files to achieve Remote Code Execution, potentially leading to complete server compromise, data theft, and lateral movement within the network.

Affected Products

• TCMAN GIM version 11.0
• tcman:gim component

Discovery Timeline

• 2025-05-06 - CVE-2025-40625 published to NVD
• 2025-05-13 - Last updated in NVD database

Technical Details for CVE-2025-40625

Vulnerability Analysis

This vulnerability (CWE-434: Unrestricted Upload of File with Dangerous Type) exists in TCMAN's GIM v11 enterprise management software. The file upload functionality fails to properly validate or restrict the types of files that can be uploaded to the server. An unauthenticated attacker can exploit this weakness to upload executable files, web shells, or other malicious content directly to the server without any authentication requirements.

The network-accessible nature of this vulnerability combined with no authentication requirements significantly increases the risk profile. Once a malicious file is uploaded, an attacker can execute it to gain a foothold on the target system, potentially escalating to full system compromise.

Root Cause

The root cause of CVE-2025-40625 is the absence of proper file type validation and content inspection in the upload functionality. The application fails to implement critical security controls including:

• File extension whitelisting or blacklisting
• MIME type verification
• Content inspection to detect malicious payloads
• Authentication requirements for file upload operations

This allows any user, including unauthenticated attackers, to upload files with dangerous extensions such as .php, .jsp, .aspx, or other executable file types that can be processed by the web server.

Attack Vector

The attack vector is network-based, requiring no user interaction or prior authentication. An attacker can craft HTTP requests containing malicious file payloads and submit them to the vulnerable upload endpoint. Once the file is successfully uploaded and stored on the server, the attacker can navigate to the uploaded file's location to trigger its execution.

The vulnerability mechanism involves sending crafted multipart/form-data requests to the file upload endpoint. The server processes these requests without validating the file type or content, allowing web shells or other executable payloads to be stored in accessible locations. For detailed technical information, refer to the INCIBE Security Notice.

Detection Methods for CVE-2025-40625

Indicators of Compromise

• Unexpected files with executable extensions (.php, .jsp, .aspx, .exe) appearing in web-accessible directories
• Unusual HTTP POST requests to file upload endpoints with suspicious content types
• Web server logs showing access to newly created files in upload directories
• Process spawning from web server processes that indicate command execution

Detection Strategies

• Monitor file upload directories for new files with executable or suspicious extensions
• Implement web application firewall (WAF) rules to detect and block attempts to upload files with dangerous extensions
• Review web server access logs for POST requests to upload endpoints followed by GET requests to unusual file paths
• Deploy file integrity monitoring on directories where uploaded files are stored

Monitoring Recommendations

• Enable detailed logging for all file upload operations including source IP, filename, and file size
• Configure alerts for any new executable files created in web-accessible directories
• Monitor for outbound connections from web server processes that may indicate successful RCE
• Implement network traffic analysis to detect command and control communications

How to Mitigate CVE-2025-40625

Immediate Actions Required

• Restrict network access to the TCMAN GIM application to trusted IP addresses only
• Implement authentication requirements for all file upload functionality if possible through network controls
• Deploy a web application firewall (WAF) with rules to block uploads of dangerous file types
• Review and remove any suspicious files from upload directories

Patch Information

Organizations should contact TCMAN directly for information about security patches addressing this vulnerability. Monitor the INCIBE Security Notice for updates regarding vendor patches and remediation guidance.

Workarounds

• Implement strict file upload validation at the network perimeter using a reverse proxy or WAF
• Configure the web server to prevent execution of uploaded files by removing execute permissions from upload directories
• Implement network segmentation to isolate systems running TCMAN GIM from critical infrastructure
• Enable application-layer filtering to block multipart/form-data requests containing suspicious file extensions

# Example: Restrict upload directory permissions and disable script execution (Apache)
# Add to .htaccess in upload directories
chmod 644 /path/to/uploads/*
# Disable PHP execution in upload directory
# php_flag engine off
# Options -ExecCGI
# RemoveHandler .php .phtml .php3 .php4 .php5 .phps