CVE-2025-41012: Tcman Gim Auth Bypass Vulnerability

CVE-2025-41012 Overview

CVE-2025-41012 is a high-severity unauthorized access vulnerability affecting TCMAN GIM v11 version 20250304. This vulnerability enables unauthenticated attackers to perform user enumeration attacks through the SOAP web service interface. By manipulating the pda:userId and pda:newPassword parameters in conjunction with the soapaction UnlockUser request to /WS/PDAWebService.asmx, attackers can determine whether specific user accounts exist on the system.

This vulnerability is classified as CWE-862 (Missing Authorization), indicating that the affected endpoint fails to implement proper access control mechanisms before exposing sensitive information about user account existence.

Critical Impact

Unauthenticated attackers can enumerate valid user accounts on the system, enabling targeted credential attacks, social engineering campaigns, or preparation for more sophisticated intrusions.

Affected Products

• TCMAN GIM v11 version 20250304
• tcman gim (all affected versions per CPE: cpe:2.3:a:tcman:gim:*:*:*:*:*:*:*:*)

Discovery Timeline

• 2025-12-02 - CVE-2025-41012 published to NVD
• 2025-12-03 - Last updated in NVD database

Technical Details for CVE-2025-41012

Vulnerability Analysis

This vulnerability represents a Missing Authorization flaw (CWE-862) in the TCMAN GIM web service layer. The affected endpoint /WS/PDAWebService.asmx exposes the UnlockUser SOAP action without implementing proper authentication or authorization checks. The service responds differently based on whether the queried user account exists, creating an oracle that attackers can leverage for user enumeration.

The CVSS 4.0 score of 8.7 (HIGH) reflects the network-accessible attack vector with no authentication requirements and high confidentiality impact. The CVSS vector string is: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

According to EPSS data from 2025-12-16, this vulnerability has a 0.066% probability of exploitation with a percentile ranking of 20.6, indicating relatively lower exploitation likelihood in the wild compared to other vulnerabilities.

Root Cause

The root cause of CVE-2025-41012 lies in the missing authorization checks within the PDAWebService.asmx web service. The UnlockUser SOAP action processes requests containing pda:userId and pda:newPassword parameters without first verifying that the requestor has appropriate permissions to perform this operation or even access user information. The service's error handling or response behavior varies based on user existence, creating an information disclosure channel that attackers can exploit.

Attack Vector

The attack vector for CVE-2025-41012 is network-based, requiring no authentication or user interaction. An attacker can craft malicious SOAP requests targeting the /WS/PDAWebService.asmx endpoint with the UnlockUser action. By iterating through potential usernames in the pda:userId parameter and analyzing the differential responses, attackers can build a list of valid user accounts.

The attack involves sending SOAP requests to the vulnerable endpoint with the soapaction UnlockUser header. The attacker supplies arbitrary values for pda:userId (the target username to enumerate) and pda:newPassword parameters. The service response differs based on whether the specified user exists, allowing the attacker to distinguish between valid and invalid usernames. This enumeration technique can be automated to rapidly identify all valid user accounts in the system, which can then be used for targeted password attacks or social engineering.

Detection Methods for CVE-2025-41012

Indicators of Compromise

• Unusual volume of SOAP requests to /WS/PDAWebService.asmx with UnlockUser action
• Multiple sequential requests with varying pda:userId parameter values from the same source
• HTTP requests containing soapaction: UnlockUser headers from untrusted or external sources
• Failed authentication attempts for accounts discovered through enumeration
• Automated scanning patterns targeting the PDAWebService endpoint

Detection Strategies

Organizations should implement web application firewall (WAF) rules to monitor and alert on suspicious patterns targeting the /WS/PDAWebService.asmx endpoint. Log analysis should focus on identifying high-frequency requests to this endpoint, particularly those with systematically varying pda:userId parameters. Security teams should correlate these events with subsequent authentication attempts to detect reconnaissance-to-attack progression.

Network intrusion detection systems (IDS) can be configured with signatures to detect SOAP requests containing the UnlockUser action targeting TCMAN GIM installations. Additionally, implementing rate limiting on the affected endpoint can help throttle enumeration attempts while alerting security teams to potential attacks.

Monitoring Recommendations

Security teams should enable detailed logging for the TCMAN GIM web service, capturing all requests to /WS/PDAWebService.asmx. Implement SIEM rules to alert on enumeration patterns, such as more than 10 requests to the UnlockUser action within a 60-second window from a single source IP. Monitor for requests originating from unexpected geographic locations or known malicious IP ranges. Consider implementing network segmentation to limit access to the web service endpoint from trusted networks only.

How to Mitigate CVE-2025-41012

Immediate Actions Required

• Restrict network access to /WS/PDAWebService.asmx to trusted IP addresses only using firewall rules
• Implement rate limiting on the affected endpoint to throttle potential enumeration attempts
• Enable enhanced logging for the PDAWebService to capture all access attempts
• Review access logs for evidence of prior exploitation or reconnaissance activity
• Apply vendor patches or updates as soon as they become available from TCMAN

Patch Information

Organizations should consult the security advisory from INCIBE-CERT for detailed remediation guidance: https://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-tcman-gim-2

Contact TCMAN directly for information about security patches addressing CVE-2025-41012. Until an official patch is available, implement the workarounds and compensating controls described below to reduce exposure risk.

Workarounds

If patching is not immediately possible, implement network-level restrictions to limit access to the vulnerable web service endpoint. Configure your web server or reverse proxy to require authentication before allowing access to /WS/PDAWebService.asmx. Consider disabling the UnlockUser SOAP action if it is not required for business operations.

# Example: Block external access to vulnerable endpoint using iptables
# Allow only internal network (adjust subnet as needed)
iptables -A INPUT -p tcp --dport 80 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP