CVE-2025-12789 is an Open Redirect vulnerability identified in Red Hat Single Sign-On (RH-SSO) version 7, specifically affecting the logout process. The vulnerability stems from improper validation of the redirect_uri parameter used in the OpenID Connect logout protocol. During logout, RH-SSO allows redirection to a URL specified by this parameter without adequately verifying whether the URL is trusted or belongs to an allowed domain. This flaw enables attackers to craft malicious logout links that redirect users to arbitrary external websites, potentially facilitating phishing attacks or other social engineering exploits by leveraging the trust users place in the legitimate RH-SSO domain. The vulnerability does not require authentication but does require user interaction to trigger the redirect. The CVSS v3.1 base score is 6.1 (medium severity), with vector AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N, indicating network attack vector, low attack complexity, no privileges required, user interaction needed, scope changed, and low impact on confidentiality and integrity but no impact on availability. No patches or exploits are currently reported, but the vulnerability poses a risk to organizations relying on RH-SSO for identity and access management, especially in environments where logout redirection is used in workflows or user interfaces.

The primary impact of this vulnerability is the potential for attackers to redirect users to malicious websites during the logout process, which can be exploited for phishing, credential harvesting, or delivering malware. Although the vulnerability does not directly compromise system availability or allow privilege escalation, it undermines user trust and the integrity of the logout flow. Organizations using RH-SSO 7 may face increased risk of social engineering attacks targeting their employees or customers. This can lead to data breaches if users are tricked into divulging sensitive information or installing malicious software. The scope of affected systems includes any deployment of RH-SSO 7 that uses the OpenID Connect logout protocol with redirect_uri parameters. Given the widespread use of Red Hat products in enterprise and government sectors, the impact could be significant in environments where secure logout and redirection are critical for session management and user experience.

To mitigate this vulnerability, organizations should implement strict validation of the redirect_uri parameter to ensure it only allows redirection to trusted, whitelisted domains. This can be done by configuring RH-SSO to enforce exact or pattern-based matching of redirect URIs during logout. Additionally, administrators should review and restrict logout redirection workflows to minimize unnecessary redirects. Monitoring and logging logout requests with redirect parameters can help detect suspicious activity. Applying any vendor-released patches or updates as soon as they become available is crucial. In the absence of patches, consider disabling or limiting the use of logout redirection features temporarily. User education on recognizing phishing attempts and suspicious redirects can also reduce the risk of exploitation. Finally, integrating web application firewalls (WAFs) to detect and block malicious redirect attempts may provide an additional layer of defense.