CVE-2025-40667 Overview
CVE-2025-40667 is a missing authorization vulnerability [CWE-862] affecting TCMAN GIM v11, a computerized maintenance management system. The flaw allows an authenticated attacker to access application functionality that is not exposed through the standard user interface. Exploitation requires modifying the HTTP response code from 302 Found to 200 OK, along with tampering with the hidden form fields hdnReadOnly and hdnUserLogin. The vulnerability results from server-side authorization checks relying on client-side response handling and hidden field values rather than enforced session privileges.
Critical Impact
An authenticated attacker with low privileges can access restricted application functionality, compromising confidentiality and integrity of maintenance management data.
Affected Products
- TCMAN GIM v11.0
- CPE: cpe:2.3:a:tcman:gim:11.0
- Vendor: TCMAN
Discovery Timeline
- 2025-05-26 - CVE-2025-40667 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-40667
Vulnerability Analysis
The vulnerability stems from improper server-side authorization enforcement in GIM v11. The application relies on HTTP redirects and hidden form fields to gate access to restricted functionality. When a user without the required privileges requests a restricted page, the server issues a 302 Found redirect and depends on client-side rendering to conceal unavailable features.
An authenticated attacker can intercept the HTTP response and change the status code to 200 OK. By additionally modifying the hidden fields hdnReadOnly and hdnUserLogin, the attacker escalates their effective role within the session. The server subsequently processes actions submitted from that page without re-validating whether the account is authorized. This is a classic broken access control pattern where trust is delegated to the client.
Root Cause
The root cause is missing authorization checks on server-side action handlers. Authorization decisions depend on client-supplied state (hdnReadOnly, hdnUserLogin) and on the client honoring redirect responses. No server-side enforcement re-verifies the session's role or permissions before executing sensitive operations.
Attack Vector
Exploitation occurs over the network and requires a valid low-privileged account. The attacker uses an intercepting proxy to modify HTTP responses and request payloads. No user interaction is required beyond the attacker's own session. See the INCIBE advisory for technical details on the vulnerable request-response flow.
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Stop Identity AttacksDetection Methods for CVE-2025-40667
Indicators of Compromise
- Unexpected POST requests submitted by low-privileged accounts to administrative endpoints in GIM v11.
- HTTP requests containing tampered hdnReadOnly or hdnUserLogin hidden fields inconsistent with the session's role.
- Application audit log entries showing configuration or data changes by accounts that lack the corresponding UI menu access.
Detection Strategies
- Enable verbose access logging on the GIM web tier and correlate user role with each accessed endpoint.
- Deploy web application firewall rules that inspect POST bodies for unauthorized values in hdnReadOnly and hdnUserLogin.
- Alert on client sessions that receive frequent 302 responses immediately followed by successful POST submissions to the redirected resource.
Monitoring Recommendations
- Continuously monitor authentication and authorization logs for privilege inconsistencies between UI-rendered and server-executed actions.
- Baseline normal per-user endpoint access and alert on deviations, particularly to administrative or maintenance-configuration URLs.
- Retain full HTTP request and response metadata to enable post-incident reconstruction of hidden-field tampering.
How to Mitigate CVE-2025-40667
Immediate Actions Required
- Contact TCMAN to obtain a patched build of GIM addressing the missing authorization defect.
- Restrict network access to the GIM application to trusted internal networks and authenticated VPN users.
- Review and reduce user privileges to enforce least privilege pending vendor remediation.
- Audit application logs for signs of prior exploitation using the indicators listed above.
Patch Information
No vendor advisory URL or patched version is listed in NVD at time of publication. Consult the INCIBE notice on TCMAN GIM vulnerabilities and contact TCMAN directly for remediation guidance and fixed release availability.
Workarounds
- Place GIM behind a reverse proxy or WAF that strips or validates hidden fields on inbound requests.
- Enforce server-side session role checks at the proxy layer for known administrative endpoints where feasible.
- Disable or lock accounts that do not require access to GIM to reduce the pool of potential authenticated attackers.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
