CVE-2025-40670 is an incorrect authorization vulnerability identified in TCMAN's GIM product, specifically version 11. The vulnerability stems from improper access control mechanisms in the web interface endpoint /PC/frmGestionUser.aspx/updateUser. An unprivileged attacker can exploit this flaw by sending a crafted POST request to this endpoint, enabling them to create new user accounts and assign extensive privileges without proper authorization checks. This effectively bypasses intended security controls, allowing privilege escalation from a low-privilege or unauthenticated state to administrative-level access within the GIM system. The vulnerability is classified under CWE-863, which relates to incorrect authorization, indicating that the system fails to enforce correct permission checks before allowing sensitive operations. The CVSS 4.0 base score is 7.1 (high severity), with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), no authentication required (AT:N), no user interaction (UI:N), and no impact on confidentiality or availability but high impact on integrity (VI:H). This suggests the attacker can manipulate system integrity by unauthorized user creation and privilege assignment, potentially leading to further compromise of the system or connected infrastructure. No known exploits are currently reported in the wild, and no patches have been published at the time of analysis. The vulnerability was reserved in April 2025 and published in June 2025, with INCIBE (Spain's National Cybersecurity Institute) as the assigner, indicating European awareness and involvement in tracking this issue.

For European organizations using TCMAN GIM v11, this vulnerability poses a significant risk to system integrity and operational security. Unauthorized creation of privileged users can lead to full administrative control over the GIM system, enabling attackers to manipulate user accounts, access sensitive management functions, and potentially pivot to other connected systems. This could disrupt business operations, compromise sensitive data indirectly through privilege abuse, and undermine trust in IT management processes. Given that GIM is likely used in enterprise or critical infrastructure environments for user and identity management, exploitation could have cascading effects on organizational security posture. The lack of required authentication and user interaction lowers the barrier for exploitation, increasing the likelihood of successful attacks if the system is exposed to untrusted networks. Although no exploits are known in the wild yet, the high severity and ease of exploitation make it a critical concern for organizations to address promptly. Additionally, the integrity impact could facilitate further attacks such as data manipulation, unauthorized access, or persistent footholds within the network.

1. Immediate mitigation should focus on restricting access to the vulnerable endpoint (/PC/frmGestionUser.aspx/updateUser) through network-level controls such as firewalls or web application firewalls (WAFs) to limit exposure to untrusted networks. 2. Implement strict access control policies and verify that only trusted, authenticated administrators can access user management functionalities. 3. Monitor logs for unusual POST requests to the updateUser endpoint, especially those originating from unprivileged accounts or unknown IP addresses, to detect potential exploitation attempts. 4. Conduct a thorough audit of existing user accounts and privileges to identify and remove any unauthorized or suspicious accounts created prior to patching. 5. Engage with TCMAN vendor support channels to obtain patches or official remediation guidance as soon as they become available. 6. If patching is delayed, consider deploying compensating controls such as multi-factor authentication (MFA) on administrative accounts and enhanced network segmentation to reduce the impact of potential compromise. 7. Educate IT and security teams about this vulnerability to ensure rapid detection and response capabilities. 8. Regularly update and test incident response plans to handle potential exploitation scenarios involving privilege escalation.