CVE-2025-30164 is a medium-severity vulnerability classified as CWE-601 (Open Redirect) affecting Icinga Web 2, an open-source monitoring web interface and framework widely used for IT infrastructure monitoring. The vulnerability exists in versions prior to 2.11.5 and between 2.12.0 and 2.12.3, allowing an attacker to craft malicious URLs that, when visited by an authenticated user or a user capable of authenticating, cause the backend to redirect the user to an arbitrary external location. This redirection can be exploited to facilitate phishing attacks, credential theft, or delivery of malicious payloads by leveraging the trust users place in the legitimate Icinga Web 2 interface. The vulnerability requires at least some level of user authentication and user interaction (clicking the crafted URL). The CVSS 3.1 base score is 4.1, reflecting a network attack vector with low complexity, requiring privileges and user interaction, and resulting in no confidentiality impact but limited integrity impact and no availability impact. No known exploits are currently in the wild, and no workarounds exist aside from upgrading to fixed versions 2.11.5 or 2.12.3 and later. This vulnerability highlights the risk of insufficient validation of redirect URLs within the application, which can be abused to redirect users to untrusted sites.

For European organizations using Icinga Web 2 for monitoring critical IT infrastructure, this vulnerability poses a moderate risk. While it does not directly compromise system confidentiality or availability, it enables attackers to conduct social engineering attacks by redirecting authenticated users to malicious sites. This can lead to credential harvesting, session hijacking, or malware delivery, potentially undermining the security of the monitoring environment and broader IT systems. Given that monitoring platforms often have privileged access and visibility into network and system health, compromising user trust in these interfaces can have cascading effects, including delayed incident detection or unauthorized access escalation. The requirement for user authentication and interaction limits the scope but does not eliminate risk, especially in environments with many users or where phishing defenses are weak. European organizations with regulatory obligations around data protection and incident response must consider the reputational and compliance implications of such attacks.

The primary mitigation is to upgrade Icinga Web 2 installations to versions 2.11.5 or 2.12.3 and above, where the vulnerability is patched. Organizations should audit their current versions and plan immediate upgrades. Additionally, implement strict URL validation and sanitization on any internal or external links generated by the monitoring interface to prevent open redirects. Employ multi-factor authentication (MFA) to reduce the risk of compromised credentials being exploited. Educate users about phishing risks, especially regarding unexpected redirects from trusted internal tools. Monitor logs for unusual redirect patterns or access attempts. Network-level controls such as web filtering and DNS filtering can help block access to known malicious domains that could be used in redirection attacks. Finally, consider isolating the monitoring interface behind VPNs or zero-trust access gateways to limit exposure to authenticated users only.