CVE-2024-14000 is a cross-site scripting (XSS) vulnerability identified in Nagios XI, a widely used IT infrastructure monitoring solution. The vulnerability exists in the Capacity Planning Report component of Nagios XI versions prior to 2024R1.1.3. It stems from improper neutralization of user-supplied input during web page generation, classified under CWE-79. Specifically, the application fails to adequately validate or escape input data before rendering it in the web interface, enabling attackers to inject malicious JavaScript code. When a victim accesses the compromised report or a crafted URL, the injected script executes in their browser context, potentially allowing attackers to hijack user sessions, steal credentials, or perform unauthorized actions within the Nagios XI environment. The CVSS 4.0 base score is 5.1 (medium severity), reflecting network attack vector, low attack complexity, no privileges required, but user interaction is necessary. No known exploits have been reported in the wild as of the publication date. The vulnerability affects the confidentiality and integrity of user sessions and data but does not directly impact system availability. Nagios XI is commonly deployed in enterprise environments for monitoring critical IT assets, making this vulnerability relevant for organizations relying on its reporting features. The lack of a patch link suggests that users should upgrade to Nagios XI 2024R1.1.3 or later once available or apply recommended mitigations to prevent exploitation.

For European organizations, exploitation of this XSS vulnerability could lead to unauthorized access to sensitive monitoring data, session hijacking, and potential lateral movement within IT environments. Since Nagios XI is often used to monitor critical infrastructure and services, attackers leveraging this vulnerability could gain insights into network topology, system statuses, and potentially manipulate monitoring data to mask malicious activities. This could undermine incident response and operational continuity. Additionally, compromised user credentials or sessions could be used to escalate privileges or access other connected systems. The requirement for user interaction limits automated exploitation but does not eliminate risk, especially in environments with many users accessing reports. The impact is particularly significant for sectors with stringent compliance requirements such as finance, healthcare, and government agencies across Europe. Disruption or data leakage in these sectors could have regulatory and reputational consequences.

European organizations should prioritize upgrading Nagios XI installations to version 2024R1.1.3 or later as soon as it becomes available. Until then, administrators should restrict access to the Capacity Planning Report component to trusted users only and consider disabling it if feasible. Implement strict input validation and output encoding on all user-supplied data within custom reports or plugins to prevent injection of malicious scripts. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers. Conduct regular security audits and penetration testing focused on web interface components. Educate users about the risks of clicking untrusted links or opening suspicious reports. Monitor web server logs for unusual requests targeting the Capacity Planning Report URLs. Finally, integrate Nagios XI monitoring with centralized security information and event management (SIEM) systems to detect anomalous activities promptly.