CVE-2025-50976 is a reflected cross-site scripting (XSS) vulnerability identified in the DNS management interface (dns.cgi) of IPFire version 2.29. The vulnerability arises due to improper sanitization of user-supplied input in the NAMESERVER, REMARK, and TLS_HOSTNAME query parameters. This lack of input validation allows an attacker to inject malicious scripts that are reflected back to the user’s browser when these parameters are processed. The vulnerability is classified under CWE-79, which pertains to improper neutralization of input during web page generation, leading to XSS attacks. The CVSS v3.1 base score is 6.1, indicating a medium severity level. The attack vector is network-based (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R), and the scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact affects confidentiality and integrity to a limited extent (C:L/I:L), with no impact on availability (A:N). No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability could be exploited by tricking a user into clicking a crafted URL containing malicious script payloads in the vulnerable parameters, which then execute in the context of the user’s browser session, potentially leading to session hijacking, credential theft, or unauthorized actions within the IPFire management interface or other trusted contexts.

For European organizations using IPFire 2.29 as a firewall or network security appliance, this vulnerability poses a risk primarily to the confidentiality and integrity of administrative sessions. Successful exploitation could allow attackers to steal session cookies or perform actions on behalf of authenticated users, potentially leading to unauthorized changes in firewall configurations or exposure of sensitive network information. Although the vulnerability does not directly impact availability, the compromise of firewall management could indirectly affect network security posture and availability. European organizations in sectors with stringent data protection requirements, such as finance, healthcare, and critical infrastructure, could face regulatory and reputational consequences if exploited. The requirement for user interaction reduces the risk somewhat but does not eliminate it, especially in environments where administrators might be targeted with phishing or social engineering attacks. The reflected XSS could also be leveraged as part of a broader attack chain, facilitating lateral movement or privilege escalation within the network.

1. Immediate mitigation should include restricting access to the IPFire DNS management interface to trusted networks and users only, ideally via VPN or secure management channels. 2. Implement strict input validation and output encoding on the server side for the NAMESERVER, REMARK, and TLS_HOSTNAME parameters to neutralize malicious scripts. 3. Apply Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in the management interface. 4. Educate administrators about the risks of clicking on untrusted links and implement phishing awareness training to reduce the likelihood of user interaction exploitation. 5. Monitor logs for unusual access patterns or repeated attempts to inject scripts via the vulnerable parameters. 6. Once available, promptly apply official patches or updates from IPFire addressing this vulnerability. 7. Consider deploying web application firewalls (WAF) with rules to detect and block reflected XSS payloads targeting the dns.cgi interface. 8. Regularly review and update firewall and network segmentation policies to minimize exposure of management interfaces.