CVE-2025-34313 is a stored cross-site scripting (XSS) vulnerability identified in IPFire, an open-source firewall distribution widely used for network security. The vulnerability exists in versions prior to 2.29 (Core Update 198) and is triggered when an authenticated user creates a user quota rule. Specifically, the QUOTA_USERS parameter, which specifies assigned users for the quota, is not properly sanitized or encoded before being stored and later rendered in the web interface. This improper neutralization of input (CWE-79) allows an attacker to inject arbitrary JavaScript code that executes in the browsers of other users who view the affected quota entry. The attack vector involves sending an HTTP POST request to /cgi-bin/urlfilter.cgi with MODE=USERQUOTA and a malicious payload in QUOTA_USERS. 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 no additional privileges or user interaction beyond viewing the affected quota entry are needed to trigger the payload. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges required beyond authentication, and no user interaction needed to execute the script once stored. The vulnerability impacts confidentiality and integrity by enabling session hijacking, credential theft, or further exploitation through the victim’s browser context. No public exploits have been reported yet, but the flaw is significant given IPFire’s role in securing network perimeters. The root cause is insufficient input validation and output encoding during web page generation, a common web application security weakness. The vulnerability was published on 2025-10-28, with no patch links currently available, emphasizing the need for prompt vendor updates or workarounds.

For European organizations, this vulnerability poses a moderate risk primarily to network security administrators and users managing IPFire firewall appliances. Successful exploitation can lead to session hijacking, theft of administrative credentials, or execution of malicious scripts within the trusted IPFire management interface. This could allow attackers to manipulate firewall rules, disrupt network traffic, or pivot to internal systems, undermining network integrity and availability. Organizations relying on IPFire for perimeter defense, especially in critical infrastructure sectors like energy, telecommunications, and government, face increased risk of targeted attacks. The requirement for authenticated access limits exposure to insider threats or attackers who have compromised low-privilege accounts. However, given IPFire’s deployment in many European SMEs and public institutions, the vulnerability could facilitate lateral movement or privilege escalation within networks. The lack of known exploits reduces immediate threat but does not eliminate risk, as stored XSS vulnerabilities are often leveraged in multi-stage attacks. Overall, the impact is medium but could escalate if combined with other vulnerabilities or social engineering tactics.

1. Upgrade IPFire installations to version 2.29 (Core Update 198) or later as soon as the patch becomes available to ensure the vulnerability is remediated. 2. Until patches are applied, restrict access to the IPFire web interface to trusted networks and users only, using network segmentation and VPNs. 3. Implement strict role-based access controls to limit which authenticated users can create or modify user quota rules. 4. Monitor IPFire logs and user activities for suspicious quota rule creations or modifications that could indicate attempted exploitation. 5. Educate administrators about the risks of stored XSS and encourage cautious handling of user inputs in the management interface. 6. Consider deploying web application firewalls (WAFs) or reverse proxies that can detect and block malicious payloads targeting the quota management endpoints. 7. Regularly audit and sanitize existing quota entries to remove any potentially malicious scripts. 8. Follow vendor advisories closely for official patches or mitigation guidance.