CVE-2024-31488 is a vulnerability identified in multiple versions of Fortinet's FortiNAC product, specifically versions 7.2.0 through 9.4.4. The flaw arises from improper neutralization of inputs during web page generation, classified under CWE-79, which corresponds to cross-site scripting (XSS). This vulnerability allows a remote attacker with authenticated access to the FortiNAC management interface to inject malicious scripts via crafted HTTP requests. Both stored and reflected XSS attacks are possible, meaning that malicious payloads can be permanently stored on the server or reflected back in responses. Successful exploitation enables attackers to execute unauthorized code or commands within the context of the victim's browser session, potentially leading to session hijacking, privilege escalation, or further compromise of the network access control environment. The vulnerability requires the attacker to have valid credentials (high privileges) and user interaction (e.g., an administrator clicking a malicious link). The CVSS v3.1 base score is 6.1, indicating medium severity, with attack vector network, low attack complexity, high privileges required, and user interaction needed. The impact affects confidentiality, integrity, and availability of the FortiNAC system. No public exploits or active exploitation have been reported as of the publication date. FortiNAC is widely used for network access control, especially in enterprise and critical infrastructure environments, making this vulnerability significant for organizations relying on Fortinet's NAC solutions.

For European organizations, the exploitation of CVE-2024-31488 could lead to unauthorized execution of scripts within the FortiNAC management interface, compromising administrative sessions and potentially allowing attackers to manipulate network access controls. This could result in unauthorized network access, data exfiltration, or disruption of network security policies. The confidentiality of sensitive network configuration data and credentials could be compromised, integrity of network access enforcement could be undermined, and availability of network access control services could be disrupted. Given FortiNAC's role in securing enterprise and critical infrastructure networks, successful exploitation could have cascading effects on operational technology environments, data centers, and corporate networks. The requirement for authenticated access limits the attack surface but does not eliminate risk, especially in environments with weak credential management or insider threats. The absence of known exploits in the wild currently reduces immediate risk but does not preclude targeted attacks or future exploit development.

1. Apply official patches and updates from Fortinet as soon as they become available to address CVE-2024-31488. 2. Restrict administrative access to FortiNAC interfaces using network segmentation, VPNs, and IP whitelisting to limit exposure. 3. Enforce strong authentication mechanisms, including multi-factor authentication (MFA), to reduce risk of credential compromise. 4. Implement strict input validation and sanitization on all user inputs within FortiNAC configurations and web interfaces. 5. Deploy Content Security Policy (CSP) headers to mitigate the impact of XSS by restricting script execution sources. 6. Monitor FortiNAC logs and network traffic for unusual activity indicative of attempted exploitation. 7. Conduct regular security awareness training for administrators to recognize and avoid phishing or social engineering attempts that could facilitate user interaction required for exploitation. 8. Review and minimize the number of users with high privileges on FortiNAC to reduce potential attack vectors. 9. Consider deploying web application firewalls (WAF) with XSS detection capabilities in front of FortiNAC management interfaces.