CVE-2025-10640 is a security vulnerability identified in EfficientLab's WorkExaminer Professional software, specifically affecting versions up to 4.0.0.52001. WorkExaminer Professional is a monitoring solution that captures user activity including screenshots and keystrokes, and provides an administrative console for managing and viewing this data. The vulnerability arises from improper enforcement of authentication on the server side. The product uses a custom protocol to communicate with an MSSQL database via stored procedures. When an administrator attempts to log in, the server calls a stored procedure and returns a value that should indicate successful authentication. However, the server does not validate this return value; instead, the client application performs the validation. This design flaw (classified as CWE-602: Client-Side Enforcement of Server-Side Security) allows an unauthenticated attacker who can reach TCP port 12306 on the WorkExaminer server to bypass the login prompt entirely by manipulating the protocol communication or responses. As a result, the attacker gains administrative access to the WorkExaminer console and can access all sensitive monitoring data, including screenshots and keystrokes of all monitored users. This compromises confidentiality and integrity of monitored data and could lead to further attacks leveraging administrative privileges. No public exploits have been reported yet, but the vulnerability is publicly disclosed as of October 21, 2025. The lack of server-side authentication checks and the exposure of a critical administrative interface over a network port make this vulnerability highly exploitable, especially in environments where network segmentation or firewall rules are insufficient. The vulnerability affects all deployments running vulnerable versions of WorkExaminer Professional that expose TCP port 12306 to untrusted networks or users.

For European organizations, the impact of CVE-2025-10640 is significant. WorkExaminer Professional is often used in corporate environments to monitor employee activity for compliance, productivity, or security purposes. An attacker exploiting this vulnerability can gain full administrative access to the monitoring server, exposing highly sensitive data such as screenshots and keystrokes, which may contain personal data, confidential business information, and credentials. This exposure risks violating data protection regulations such as the GDPR, potentially leading to legal penalties and reputational damage. Furthermore, administrative control over the monitoring system allows attackers to manipulate or delete logs, hide their presence, or pivot to other internal systems, increasing the risk of broader compromise. The vulnerability also undermines trust in monitoring solutions and may disrupt operational security processes. Organizations with remote or poorly segmented networks are particularly vulnerable if TCP port 12306 is accessible beyond trusted internal users. The absence of authentication requirements and the ability to bypass login controls make this a critical threat to confidentiality, integrity, and availability of monitoring infrastructure in European enterprises.

To mitigate CVE-2025-10640, European organizations should implement the following specific measures: 1) Immediately restrict network access to TCP port 12306 to trusted administrative hosts only, using firewall rules, VPNs, or network segmentation to prevent unauthorized access. 2) Monitor network traffic and logs for unusual connections or attempts to access the WorkExaminer server on port 12306, enabling early detection of exploitation attempts. 3) Disable or remove any unnecessary exposure of the WorkExaminer administrative console on public or untrusted networks. 4) Engage with EfficientLab to obtain patches or updates that enforce proper server-side authentication validation; apply these updates as soon as they become available. 5) Conduct an internal audit of all WorkExaminer deployments to identify vulnerable versions and exposure levels. 6) Consider deploying additional endpoint detection and response (EDR) tools to detect suspicious activity related to monitoring software manipulation. 7) Educate IT and security teams about this vulnerability to ensure rapid response and remediation. 8) Review and enhance overall network security architecture to limit lateral movement and access to critical monitoring infrastructure. These targeted actions go beyond generic advice by focusing on access control, monitoring, and vendor coordination specific to this vulnerability.