CVE-2025-10640 is a critical authentication bypass vulnerability in EfficientLab's WorkExaminer Professional software, affecting versions up to 4.0.0.52001. The WorkExaminer Professional console requires administrators to authenticate before gaining access; however, the underlying issue is that the server does not perform proper server-side validation of authentication requests. Instead, the system relies on client-side enforcement of server-side security, specifically validating the return value of a stored procedure call on the MSSQL database only on the client side. An attacker with network access to TCP port 12306 can send crafted requests that bypass the login prompt entirely, gaining administrative privileges on the server. This administrative access exposes all sensitive monitoring data collected by WorkExaminer, including screenshots and keystroke logs of all monitored users, posing a severe confidentiality and integrity risk. The vulnerability is remotely exploitable without any authentication or user interaction, making it highly dangerous. The CVSS v3.1 score of 9.8 reflects the critical impact on confidentiality, integrity, and availability, combined with the ease of exploitation and network attack vector. No patches or exploits are currently publicly available, but the vulnerability is published and should be treated with urgency.

For European organizations, this vulnerability poses a significant risk to employee privacy and corporate data security. WorkExaminer Professional is used for employee monitoring, so unauthorized administrative access could lead to exposure of sensitive personal data, violating GDPR and other privacy regulations. The compromise could also allow attackers to manipulate monitoring data, undermining trust in internal security controls. Additionally, attackers gaining full administrative access could disrupt monitoring services, impacting operational oversight. The breach of keystroke logs and screenshots could expose confidential business information, intellectual property, and credentials, potentially facilitating further attacks. Given the critical severity and remote exploitability, organizations face a high risk of data breaches, regulatory penalties, and reputational damage if this vulnerability is exploited.

European organizations using WorkExaminer Professional should immediately restrict network access to TCP port 12306 to trusted administrative hosts only, ideally via firewall rules or network segmentation. Until a vendor patch is released, disabling remote administrative access or using VPNs with strong authentication can reduce exposure. Monitoring network traffic for unusual connections or authentication bypass attempts on port 12306 is recommended. Organizations should audit existing deployments to identify affected versions and upgrade to a patched version once available. Implementing additional network-level authentication or multi-factor authentication around the management interface can provide defense in depth. Regularly reviewing logs for unauthorized access attempts and preparing incident response plans for potential exploitation is critical. Finally, organizations should engage with EfficientLab for timely patch information and updates.