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 resides in the Percentile Calculator menu, where user-supplied input is not properly validated or escaped before being incorporated into web pages. This improper neutralization of input (CWE-79) allows an attacker to inject arbitrary JavaScript code that executes in the context of the victim's browser session. The vulnerability is remotely exploitable over the network without requiring authentication, but it does require user interaction, such as clicking on a maliciously crafted URL or link. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:L), and user interaction required (UI:P). The impact is limited to confidentiality and integrity within the browser context, with no direct impact on availability or system-level privileges. Although no known exploits are currently reported in the wild, the vulnerability poses a risk of session hijacking, theft of sensitive information, or execution of unauthorized actions within the Nagios Network Analyzer interface. The lack of vendor patch links suggests that a fix may be forthcoming or that users should upgrade to version 2024R1 or later. The vulnerability’s medium severity score (5.1) reflects the moderate risk posed by this XSS flaw in a critical network monitoring product.

For European organizations, this vulnerability could have significant consequences, especially for those relying on Nagios Network Analyzer to monitor critical network infrastructure. Successful exploitation could allow attackers to execute malicious scripts in the context of authenticated users, potentially leading to session hijacking, unauthorized access to sensitive monitoring data, or manipulation of network analysis results. This could degrade the integrity and confidentiality of network monitoring operations, impacting incident response and network reliability. Organizations in sectors such as finance, energy, telecommunications, and government are particularly at risk due to their reliance on continuous and accurate network monitoring. Additionally, the vulnerability could be leveraged as a foothold for further attacks within the network if attackers gain access to administrative sessions. Although the vulnerability does not directly affect system availability, the indirect effects on operational security and trustworthiness of monitoring data could be substantial.

European organizations should implement the following specific mitigation measures: 1) Upgrade Nagios Network Analyzer to version 2024R1 or later as soon as the patch is available to eliminate the vulnerability. 2) Until a patch is applied, restrict access to the Percentile Calculator menu to trusted users and limit exposure by network segmentation or firewall rules. 3) Implement strict input validation and output encoding on all user inputs within the application, particularly in custom or extended deployments. 4) Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in the browser context. 5) Educate users to recognize and avoid clicking on suspicious links that could trigger XSS attacks. 6) Monitor web server and application logs for unusual input patterns or attempted script injections. 7) Consider using web application firewalls (WAFs) with rules tailored to detect and block XSS payloads targeting Nagios Network Analyzer. These steps will reduce the attack surface and mitigate the risk until a full patch is applied.