CVE-2024-13995: 
Nagios XI vulnerability analysis and mitigation

CVE-2024-13995 is a sensitive information disclosure vulnerability in Nagios XI that allows authenticated users with low privileges to access sensitive user account data they should not be permitted to view. The vulnerability is confirmed in Nagios XI versions 2024R1.1 and 2024R1.1.1, and affects all versions prior to 2024R1.1.2. It was published on October 30, 2025, and assigned by VulnCheck. The vulnerability carries a CVSS v3.1 base score of 8.8 (High) and a CVSS v4.0 base score of 7.1 (High) (Nagios Security, VulnCheck Advisory).

The root cause is classified as CWE-497 (Exposure of Sensitive System Information to an Unauthorized Control Sphere), where the application improperly exposes sensitive user account data — including API keys and hashed passwords — to authenticated users who lack authorization to access that information. The attack vector is network-based, requires low privileges (a valid authenticated session), no user interaction, and low attack complexity, making it straightforward to exploit once an attacker has any valid account. The vulnerability likely stems from insufficient access control enforcement on API endpoints or administrative data views that return more user account information than the requesting user's role should permit (VulnCheck Advisory, Nagios Changelog).

Successful exploitation allows a low-privileged authenticated attacker to obtain API keys belonging to other users (including potentially administrative accounts) and hashed passwords, which can be used for unauthorized API access, privilege escalation, or offline password cracking attempts. Compromised API keys could enable an attacker to perform actions on behalf of higher-privileged users, potentially leading to full system compromise of the Nagios XI monitoring infrastructure. Given that Nagios XI typically has visibility into and credentials for a broad range of monitored network infrastructure, a compromise of this system could facilitate significant lateral movement across an organization's environment (VulnCheck Advisory).

There is currently no public proof-of-concept exploit code and no evidence of in-the-wild exploitation (VulnCheck Advisory). The EPSS score is approximately 0.44%, indicating a low but non-negligible probability of exploitation in the near term. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. No threat actor attribution has been reported at this time.

1. Reconnaissance: Identify internet-facing or internally accessible Nagios XI instances running versions 2024R1.1 or 2024R1.1.1 using network scanning tools or service banners.
2. Obtain low-privilege credentials: Acquire any valid Nagios XI user account (e.g., a read-only monitoring account), which may be obtained through phishing, credential stuffing, or insider access.
3. Authenticate to Nagios XI: Log in to the Nagios XI web interface or API using the low-privilege account.
4. Access sensitive data endpoint: Query the API endpoint or administrative interface that improperly returns user account information, including API keys and hashed passwords for other users.
5. Extract API keys: Use harvested API keys to authenticate as other users (including administrators) and perform unauthorized actions via the Nagios XI API.
6. Crack password hashes: Submit extracted password hashes to offline cracking tools (e.g., Hashcat, John the Ripper) to recover plaintext passwords for further account compromise or credential reuse attacks (VulnCheck Advisory).

• Network: Unusual or repeated API requests from low-privileged user accounts to administrative or user-management endpoints; API calls querying user account data outside of normal operational patterns.
• Logs: Nagios XI access logs showing authenticated low-privilege users accessing user account management or API key listing endpoints; anomalous API authentication events using credentials of users who are not actively logged in.
• Behavioral: Multiple API authentication attempts using keys belonging to different user accounts from a single source IP; login attempts using credentials that match hashed passwords extracted from the system.

The primary remediation is to upgrade Nagios XI to version 2024R1.1.2 or later, which addresses the improper access control allowing unauthorized disclosure of sensitive account data (Nagios Security, Nagios Changelog). After upgrading, administrators should immediately rotate all API keys and reset user passwords as a precautionary measure, since exposure may have occurred in affected versions. Additionally, implement strict least-privilege access controls, limit the number of accounts with access to the Nagios XI interface, and monitor for any signs of unauthorized API usage or account access.