CVE-2024-13998 is a vulnerability identified in Nagios XI, a widely used IT infrastructure monitoring solution. The flaw exists in versions prior to 2024R1.1.3 and involves the unintended disclosure of sensitive user account information, including API keys and hashed passwords, to authenticated users who should not have access to such data. This vulnerability stems from improper access control mechanisms that fail to adequately segregate sensitive information from users with limited privileges. The exposure of API keys can allow attackers to abuse API privileges, potentially manipulating monitoring data or configurations, while access to hashed passwords enables offline cracking attempts that could lead to full account compromise. The vulnerability is classified under CWE-497, which concerns exposure of sensitive system information to unauthorized control spheres. The CVSS 4.0 base score is 6.0 (medium severity), reflecting network attack vector, low attack complexity, partial authentication required, no user interaction, and high confidentiality impact. The vulnerability does not affect integrity or availability directly but poses a significant confidentiality risk. No known exploits have been reported in the wild, but the existence of a similar vulnerability (CVE-2024-13995) with an incomplete fix suggests the underlying issue is complex. The recommended remediation is to upgrade Nagios XI to version 2024R1.1.3 or later, which addresses this vulnerability. Additionally, organizations should review user roles and permissions to minimize exposure of sensitive data and monitor API usage for anomalies.

For European organizations, the exposure of API keys and hashed passwords in Nagios XI can lead to unauthorized access to monitoring systems, manipulation of monitoring data, and potential lateral movement within networks. Compromise of monitoring infrastructure can disrupt incident detection and response, increasing the risk of prolonged undetected breaches. Organizations in sectors reliant on continuous monitoring, such as finance, healthcare, energy, and critical infrastructure, face elevated risks. The confidentiality breach could also lead to regulatory compliance issues under GDPR, as sensitive user credentials are exposed. Attackers exploiting this vulnerability could gain footholds to escalate privileges or exfiltrate sensitive operational data. The medium severity rating indicates a significant but not catastrophic risk, emphasizing the need for timely patching and access control reviews to prevent exploitation.

1. Upgrade Nagios XI installations to version 2024R1.1.3 or later immediately to apply the official patch addressing CVE-2024-13998. 2. Conduct a thorough audit of user accounts and roles within Nagios XI to ensure that only necessary personnel have access to sensitive information, especially API keys and password hashes. 3. Implement strict role-based access controls (RBAC) to limit exposure of sensitive data to the minimum required users. 4. Monitor API usage logs for unusual or unauthorized activity that could indicate abuse of exposed API keys. 5. Enforce strong password policies and consider multi-factor authentication (MFA) for Nagios XI user accounts to mitigate risks from compromised credentials. 6. Regularly review and rotate API keys to reduce the window of opportunity for attackers. 7. Employ network segmentation to isolate monitoring infrastructure from less trusted network zones. 8. Stay informed about updates from Nagios and apply security patches promptly. 9. Consider deploying intrusion detection systems (IDS) to detect anomalous behavior related to monitoring system access.