CVE-2025-64239 identifies a Cross-Site Request Forgery (CSRF) vulnerability in the Yoav Farhi RTL Tester software, affecting all versions up to and including 1.2. CSRF vulnerabilities occur when a web application does not adequately verify that a state-changing request originates from a legitimate user action, allowing attackers to craft malicious web requests that execute with the privileges of an authenticated user. In this case, the RTL Tester lacks sufficient anti-CSRF protections, such as synchronizer tokens or same-site cookie attributes, enabling attackers to induce users to unknowingly perform actions like configuration changes or test executions. The vulnerability does not require user interaction beyond the victim being authenticated and visiting a malicious site. No public exploits have been reported, and no CVSS score has been assigned yet. The absence of patch links suggests that a fix may not be available at the time of publication, increasing the importance of interim mitigations. The vulnerability primarily impacts the integrity of the application by allowing unauthorized commands and could also affect availability if critical operations are manipulated. Given the product's niche use in software testing environments, the attack surface is limited to organizations using RTL Tester in their development or QA workflows. However, if the tool is exposed on internal or external networks, the risk increases. The vulnerability was reserved in late October 2025 and published in mid-December 2025, indicating recent discovery and disclosure.

For European organizations, the impact of this CSRF vulnerability depends on the extent of RTL Tester deployment. Organizations using RTL Tester for software testing or quality assurance could face unauthorized changes to test configurations or execution of unintended tests, potentially disrupting development pipelines and causing delays. If the tool integrates with other systems or automation workflows, attackers could leverage CSRF to indirectly affect broader processes, impacting integrity and availability of development environments. Confidentiality impact is limited as CSRF does not inherently expose data but could be combined with other vulnerabilities for escalation. The lack of known exploits reduces immediate risk, but the vulnerability could be exploited in targeted attacks, especially in organizations with lax internal network segmentation or insufficient web application protections. European countries with strong software development sectors and high adoption of developer tools—such as Germany, France, the United Kingdom, the Netherlands, and Sweden—are more likely to be affected. The vulnerability could also pose risks to critical infrastructure sectors relying on RTL Tester for software validation if attackers manipulate testing outcomes or configurations.

To mitigate CVE-2025-64239, organizations should implement robust anti-CSRF protections within RTL Tester once patches become available. Until then, practical steps include: 1) Restricting access to the RTL Tester interface to trusted internal networks and VPNs to reduce exposure. 2) Employing web application firewalls (WAFs) with rules to detect and block CSRF attack patterns. 3) Encouraging users to log out of RTL Tester sessions when not in use to minimize authenticated session exposure. 4) Monitoring application logs for unusual or unauthorized requests indicative of CSRF exploitation attempts. 5) Applying browser security features such as SameSite cookie attributes if configurable. 6) Educating users about the risks of visiting untrusted websites while authenticated to internal tools. 7) Segregating testing environments from production and sensitive systems to limit impact. 8) Coordinating with the vendor or community to obtain patches or updates addressing the vulnerability promptly. These measures go beyond generic advice by focusing on access control, monitoring, and user behavior to reduce attack surface and impact.