CVE-2024-6592 is a critical security vulnerability classified under CWE-306 (Missing Authentication for Critical Function) affecting the WatchGuard Authentication Gateway and its Single Sign-On (SSO) Clients on Windows and MacOS platforms. The vulnerability stems from an incorrect authorization mechanism in the protocol communication between the Authentication Gateway (also known as the Single Sign-On Agent) and the Single Sign-On Clients. This flaw enables an attacker to bypass authentication controls entirely, granting unauthorized access without requiring any credentials, privileges, or user interaction. The affected products include WatchGuard Authentication Gateway versions up to 12.10.2, Windows Single Sign-On Client versions up to 12.7, and MacOS Single Sign-On Client versions up to 12.5.4. The vulnerability has been assigned a CVSS v3.1 base score of 9.1, reflecting its critical severity due to network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction needed (UI:N). The impact on confidentiality and integrity is high, while availability remains unaffected. Although no known exploits have been reported in the wild yet, the vulnerability's nature makes it a prime target for attackers seeking to gain unauthorized access to enterprise environments. The vulnerability could allow adversaries to impersonate legitimate users, access sensitive resources, and potentially move laterally within compromised networks. The lack of authentication on a critical function in the SSO process undermines the security posture of organizations relying on WatchGuard’s identity and access management solutions. This necessitates urgent remediation once patches become available, alongside interim mitigations such as network segmentation and enhanced monitoring.

For European organizations, this vulnerability poses a significant risk of unauthorized access to internal systems protected by WatchGuard’s Authentication Gateway and Single Sign-On Clients. Successful exploitation could lead to compromise of user credentials, unauthorized data access, and potential lateral movement within corporate networks. This can result in data breaches involving sensitive personal data protected under GDPR, intellectual property theft, and disruption of business operations. Organizations in sectors such as finance, healthcare, government, and critical infrastructure, which often deploy WatchGuard solutions for secure authentication, are particularly at risk. The critical nature of the vulnerability means attackers can exploit it remotely without any user interaction or prior access, increasing the likelihood of widespread impact. The absence of known exploits in the wild currently provides a window for proactive defense, but the high CVSS score indicates that once weaponized, the vulnerability could be rapidly exploited. This could also affect trust in identity management systems and complicate compliance with European cybersecurity regulations.

1. Monitor WatchGuard’s official channels closely for security advisories and promptly apply patches or updates once released for Authentication Gateway and Single Sign-On Clients. 2. Until patches are available, implement network segmentation to isolate authentication infrastructure from less trusted network segments, reducing exposure. 3. Employ strict access controls and multi-factor authentication (MFA) on systems interacting with the Authentication Gateway to add layers of defense. 4. Enable detailed logging and continuous monitoring of authentication events to detect anomalous or unauthorized access attempts indicative of exploitation. 5. Conduct internal audits to identify all instances of WatchGuard Authentication Gateway and Single Sign-On Clients within the environment to ensure comprehensive coverage. 6. Consider temporary disabling or restricting use of vulnerable SSO clients in high-risk environments if feasible. 7. Educate IT and security teams about the vulnerability’s characteristics to improve incident response readiness. 8. Review and update incident response plans to include scenarios involving authentication bypass and lateral movement. 9. Collaborate with WatchGuard support for guidance and potential workarounds if immediate patching is not possible.