CVE-2025-32918 is a medium-severity vulnerability identified in Checkmk, a popular IT infrastructure monitoring software developed by Checkmk GmbH. The flaw is categorized under CWE-140, which involves improper neutralization of delimiters. Specifically, this vulnerability arises from improper neutralization of Livestatus command delimiters in the autocomplete endpoint within the RestAPI of Checkmk versions prior to 2.4.0p6, 2.3.0p35, 2.2.0p44, and the end-of-life 2.1.0 version. Livestatus is a component used by Checkmk to query monitoring data efficiently. The vulnerability allows an authenticated user to inject arbitrary Livestatus commands by exploiting the improper handling of delimiters in the autocomplete endpoint. This injection can lead to unauthorized command execution within the context of Livestatus queries, potentially enabling attackers to manipulate monitoring data or interfere with monitoring operations. The vulnerability requires the attacker to have authenticated access with at least low privileges (PR:L) and does not require user interaction (UI:N). The attack vector is network-based (AV:N) with low attack complexity (AC:L). The impact on confidentiality, integrity, and availability is low to limited but present (VC:L, VI:L, VA:L). No known exploits are currently reported in the wild, and no patches have been explicitly linked yet. The CVSS 4.0 score is 5.3, reflecting a medium severity level. This vulnerability highlights the risks associated with insufficient input validation and delimiter neutralization in API endpoints, especially those that interface with backend query engines like Livestatus.

For European organizations using Checkmk for infrastructure monitoring, this vulnerability poses a risk of unauthorized manipulation of monitoring data or commands by authenticated users with limited privileges. Such manipulation could lead to inaccurate monitoring results, delayed detection of critical incidents, or false alerts, potentially impacting operational decision-making and incident response. While the vulnerability does not allow unauthenticated access or require user interaction, the ability to inject arbitrary Livestatus commands could be leveraged by insider threats or compromised accounts to disrupt monitoring services or exfiltrate sensitive monitoring data. In critical infrastructure sectors such as energy, finance, healthcare, and telecommunications, where monitoring accuracy and availability are paramount, exploitation could degrade service reliability or mask ongoing attacks. However, the medium severity and limited impact on confidentiality and availability suggest that the threat is moderate, but still significant enough to warrant prompt remediation to maintain trust in monitoring systems and prevent escalation.

1. Upgrade Checkmk installations to the latest patched versions beyond 2.4.0p6, 2.3.0p35, or 2.2.0p44 as soon as they become available from Checkmk GmbH to ensure the vulnerability is addressed. 2. Restrict access to the RestAPI autocomplete endpoint to only trusted and necessary users, minimizing the attack surface. 3. Implement strict role-based access controls (RBAC) to limit authenticated user privileges, ensuring that users with access to the vulnerable endpoint have minimal necessary permissions. 4. Monitor API usage logs for unusual or suspicious Livestatus command patterns that could indicate attempted exploitation. 5. Employ network segmentation and firewall rules to limit exposure of the Checkmk RestAPI to internal networks or VPNs only. 6. Conduct regular security audits and penetration testing focusing on API endpoints and input validation mechanisms. 7. If immediate patching is not possible, consider disabling the autocomplete feature in the RestAPI or applying custom input validation filters to neutralize delimiter injection attempts.