CVE-2025-34307 is a stored cross-site scripting (XSS) vulnerability identified in IPFire, an open-source firewall distribution widely used for network security. The flaw exists in versions prior to 2.29 (Core Update 198) and is triggered when an authenticated user updates the firewall country search defaults. Specifically, the vulnerability arises from improper neutralization of input in the pienumber parameter, which specifies the default number of countries to display in the firewall log country search. This parameter is submitted via an HTTP POST request to /cgi-bin/logs.cgi/firewalllogcountry.dat and is stored without proper sanitization or encoding. Consequently, malicious JavaScript injected into this parameter is rendered and executed in the web interface context of other users who access the firewall country search settings. Because the vulnerability is stored, the malicious script persists and can affect multiple users over time. Exploitation requires the attacker to have authenticated access to the IPFire web interface but does not require additional user interaction beyond viewing the affected page. The vulnerability can lead to session hijacking, unauthorized actions, or information disclosure within the administrative interface. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges required beyond authentication, and no user interaction needed, with limited confidentiality, integrity, and availability impact. No public exploits are currently known, but the vulnerability poses a moderate risk due to the potential for privilege escalation and lateral movement within affected networks.

For European organizations, the impact of CVE-2025-34307 can be significant, especially for those relying on IPFire as a critical network security appliance. Successful exploitation could allow attackers with valid credentials to execute arbitrary JavaScript in the context of other administrative users, potentially leading to session hijacking, theft of sensitive credentials, or unauthorized configuration changes. This could compromise the integrity and availability of firewall policies, exposing networks to further attacks or data breaches. Given that IPFire is often deployed in small to medium enterprises, government agencies, and educational institutions across Europe, the vulnerability could affect a broad range of sectors. The stored nature of the XSS increases the risk of persistent compromise and lateral movement within the network. Additionally, the vulnerability could be leveraged in targeted attacks against organizations with high-value assets or critical infrastructure, amplifying the potential damage. Although exploitation requires authentication, insider threats or compromised credentials could facilitate attacks, making this a relevant concern for European organizations with stringent security and compliance requirements.

To mitigate CVE-2025-34307, European organizations should immediately upgrade IPFire installations to version 2.29 (Core Update 198) or later, where the vulnerability is addressed. If upgrading is not immediately feasible, administrators should restrict access to the IPFire web interface to trusted networks and users only, employing network segmentation and VPNs to limit exposure. Implement multi-factor authentication (MFA) for all IPFire administrative accounts to reduce the risk of credential compromise. Regularly audit user accounts and access logs to detect suspicious activity. Additionally, administrators can monitor and sanitize inputs related to the pienumber parameter manually or via custom web application firewalls (WAFs) as a temporary measure. Educate users with administrative access about the risks of stored XSS and encourage cautious behavior when interacting with firewall configuration interfaces. Finally, maintain up-to-date backups of firewall configurations to enable rapid recovery in case of compromise.