CVE-2025-42616 identifies a Cross-Site Request Forgery (CSRF) vulnerability in the CIRCL Vulnerability-Lookup application versions before 2.18.0. The vulnerability stems from certain endpoints that modify application state—such as database entries, user data, or configurations—being accessible via HTTP GET requests without requiring a CSRF token. Normally, state-changing operations should be protected by requiring POST requests and validating CSRF tokens to ensure that requests originate from legitimate users. However, in this case, the application accepted GET requests for these operations, which violates RESTful best practices and security principles. An attacker can exploit this by luring an authenticated user to a malicious website that triggers crafted GET requests, causing the user's browser to unknowingly perform unauthorized actions within their authenticated session. This could include privilege escalation, unauthorized configuration changes, or other malicious modifications. The vulnerability is rated high severity with a CVSS 4.0 score of 7.0, reflecting its network attack vector, low attack complexity, partial authentication required, user interaction needed, and high impact on confidentiality and integrity. The patch released in version 2.18.0 enforces that all state-changing endpoints require HTTP POST methods and valid CSRF tokens, effectively mitigating the risk by preventing cross-site GET request exploitation. No known exploits are currently reported in the wild, but the vulnerability poses a significant risk if left unpatched, especially in environments where users have elevated privileges or sensitive configurations are managed via Vulnerability-Lookup.

For European organizations, this vulnerability could lead to unauthorized changes in security configurations, user privileges, or critical vulnerability data managed through Vulnerability-Lookup. Such unauthorized modifications can undermine the integrity and confidentiality of vulnerability management processes, potentially allowing attackers to hide or manipulate vulnerability data, escalate privileges, or disrupt security operations. The exploitation requires an authenticated user to visit a malicious site, which is feasible in environments with web access and user interaction. Given the critical role of vulnerability management in cybersecurity, successful exploitation could weaken an organization's security posture, increase exposure to further attacks, and complicate incident response efforts. Organizations in sectors with stringent regulatory requirements, such as finance, healthcare, and critical infrastructure, may face compliance risks if unauthorized changes go undetected. Additionally, the vulnerability could be leveraged as part of a broader attack chain, amplifying its impact.

European organizations should immediately upgrade Vulnerability-Lookup to version 2.18.0 or later, where the vulnerability is patched. Until the upgrade is applied, organizations should implement compensating controls such as restricting access to the Vulnerability-Lookup application to trusted networks and users, employing web application firewalls (WAFs) to detect and block suspicious GET requests that attempt state changes, and enforcing strict session management and monitoring for unusual activity. Security teams should audit logs for unexpected state-changing operations initiated via GET requests. User education to avoid clicking on untrusted links while authenticated can reduce risk. Additionally, reviewing and hardening CSRF protections across all web applications, ensuring that all state-changing endpoints require POST methods and CSRF tokens, will help prevent similar vulnerabilities. Regular vulnerability scanning and penetration testing should verify the effectiveness of these mitigations.