CVE-2025-40664 is a critical security vulnerability identified in version 11 of the TCMAN GIM product. The vulnerability is classified under CWE-306, which denotes a missing authentication for a critical function. Specifically, this flaw allows an unauthenticated attacker to access and invoke sensitive endpoints within the application: /frmGestionUser.aspx/GetData, /frmGestionUser.aspx/updateUser, and /frmGestionUser.aspx/DeleteUser. These endpoints appear to be related to user management functions, including retrieving user data, updating user information, and deleting users. The absence of any authentication mechanism means that an attacker can perform these actions without any credentials or prior access, effectively bypassing all access controls. The CVSS 4.0 base score of 9.3 (critical) reflects the high severity of this vulnerability, with an attack vector of network (AV:N), no required privileges (PR:N), no user interaction (UI:N), and high impact on confidentiality and integrity (VC:H, VI:H). The vulnerability does not require any authentication or user interaction, making it trivially exploitable remotely. Although no known exploits are currently reported in the wild, the nature of the vulnerability suggests that exploitation could lead to unauthorized data disclosure, unauthorized modification of user accounts, and potentially complete compromise of the user management system. This could facilitate further lateral movement or privilege escalation within affected environments. The vulnerability was published on May 26, 2025, and assigned by INCIBE, a recognized cybersecurity entity. No patches or mitigations have been linked yet, indicating that affected organizations must prioritize risk mitigation and monitoring until a fix is available.

For European organizations using TCMAN GIM v11, this vulnerability poses a significant risk. Unauthorized access to user management functions can lead to severe consequences including data breaches involving personal or sensitive user information, disruption of user account integrity, and potential deletion of user accounts, which could interrupt business operations. Given the criticality of user management in enterprise environments, exploitation could enable attackers to create backdoors, escalate privileges, or disrupt authentication systems. This is particularly concerning for sectors with strict data protection regulations such as GDPR, where unauthorized data access or modification can result in substantial legal and financial penalties. Additionally, organizations in critical infrastructure sectors or those handling sensitive data may face operational risks and reputational damage. The ease of exploitation and lack of authentication requirements increase the likelihood of attacks, especially in environments where TCMAN GIM is exposed to external networks or insufficiently segmented internal networks.

1. Immediate network-level controls: Restrict access to the TCMAN GIM application endpoints using firewalls or network segmentation to limit exposure only to trusted internal systems or VPN users. 2. Implement Web Application Firewall (WAF) rules to detect and block unauthorized access attempts to the vulnerable endpoints. 3. Conduct thorough access reviews and monitor logs for any suspicious activity related to the affected URLs, focusing on unusual or unauthenticated requests. 4. If possible, disable or restrict the vulnerable endpoints temporarily until an official patch is released. 5. Engage with the vendor (TCMAN) for timely updates or patches and apply them as soon as they become available. 6. Employ compensating controls such as multi-factor authentication (MFA) at the network or application gateway level to add an authentication barrier. 7. Educate IT and security teams about the vulnerability to ensure rapid detection and response to any exploitation attempts. 8. Consider deploying intrusion detection/prevention systems (IDS/IPS) tuned to detect exploitation patterns of this vulnerability.