CVE-2023-7319 is a cross-site scripting (XSS) vulnerability identified in Nagios Network Analyzer, a widely used network monitoring and analysis tool. The vulnerability specifically affects versions prior to 2024R1 and is located in the Percentile Calculator menu component. The root cause is insufficient validation and escaping of user-supplied input, which allows an attacker to inject arbitrary JavaScript code into the web interface. When a victim interacts with a crafted URL or input, the malicious script executes within their browser context, potentially enabling session hijacking, theft of sensitive information, or unauthorized actions on behalf of the user. The vulnerability requires no authentication (AV:N) but does require user interaction (UI:P), such as clicking a malicious link. The attack complexity is low (AC:L), and privileges required are low (PR:L), indicating that an attacker with limited access could exploit this flaw. The vulnerability impacts confidentiality, integrity, and availability to a limited extent, as it primarily targets user sessions and data accessible through the web interface. No known exploits have been reported in the wild to date, but the presence of this vulnerability in a critical network monitoring tool poses a tangible risk. The CVSS 4.0 score of 5.1 reflects a medium severity level, emphasizing the need for timely remediation. Nagios Network Analyzer is commonly deployed in enterprise environments, including many European organizations, to monitor network health and performance, making this vulnerability relevant for critical infrastructure and IT operations.

For European organizations, exploitation of CVE-2023-7319 could lead to unauthorized access to sensitive monitoring data, session hijacking of administrative users, and potential lateral movement within the network if attacker-controlled scripts execute with elevated privileges. This could compromise the integrity and confidentiality of network monitoring data, impacting incident response and network visibility. Given Nagios Network Analyzer’s role in monitoring critical infrastructure and enterprise networks, disruption or manipulation of monitoring data could delay detection of other attacks or outages. The vulnerability’s medium severity suggests moderate risk but should not be underestimated, especially in sectors such as finance, energy, telecommunications, and government where network monitoring is vital. Additionally, the requirement for user interaction means phishing or social engineering could be used to facilitate exploitation, increasing the attack surface. The absence of known exploits in the wild provides a window for proactive mitigation, but organizations should act swiftly to prevent potential targeted attacks.

1. Apply official patches or updates from Nagios as soon as they become available for version 2024R1 or later, which address this XSS vulnerability. 2. Until patches are applied, restrict access to the Nagios Network Analyzer web interface, especially the Percentile Calculator menu, using network segmentation, VPNs, or IP whitelisting to limit exposure. 3. Deploy a web application firewall (WAF) with robust XSS detection and prevention rules to filter malicious input targeting this vulnerability. 4. Implement Content Security Policy (CSP) headers to reduce the impact of any injected scripts by restricting script sources. 5. Educate users and administrators about the risks of clicking untrusted links and the importance of verifying URLs before interaction. 6. Monitor web server logs and application logs for unusual input patterns or repeated attempts to exploit XSS vectors. 7. Conduct regular security assessments and penetration testing focused on web application vulnerabilities in Nagios deployments. 8. Consider disabling or limiting the use of the Percentile Calculator menu if it is not essential to operations, reducing the attack surface.