CVE-2025-34175 is a reflected cross-site scripting (XSS) vulnerability identified in Netgate's pfSense Community Edition (CE) version 7.0.8_2, specifically within the Suricata integration web page located at /usr/local/www/suricata/suricata_filecheck.php. The vulnerability stems from improper neutralization of input during web page generation (CWE-79), where the 'filehash' parameter is directly embedded into the HTML response without adequate sanitization or encoding of HTML special characters. This flaw allows an attacker to craft a malicious URL containing a payload in the 'filehash' parameter that, when visited by an authenticated user, executes arbitrary JavaScript in the context of the pfSense web interface. The attack vector is network-based, requiring no privileges but does require user interaction, such as clicking on a malicious link. The impact is primarily on confidentiality, with potential for session hijacking, theft of authentication tokens, or performing unauthorized actions on behalf of the victim within the pfSense management console. The vulnerability has a CVSS 4.0 score of 5.1, indicating medium severity, with limited impact on integrity and availability. No public exploits have been reported yet, but the presence of Suricata IDS/IPS functionality in pfSense installations increases the attack surface. The vulnerability highlights the importance of proper input validation and output encoding in web applications, especially in security-critical network management tools.

For European organizations, this vulnerability poses a moderate risk primarily to the confidentiality of network management sessions. Successful exploitation could allow attackers to hijack authenticated sessions of network administrators, potentially leading to unauthorized configuration changes, disabling of security controls, or exposure of sensitive network information. Organizations relying on pfSense CE for firewalling and intrusion detection, especially those integrating Suricata, could face targeted attacks exploiting this flaw. The requirement for user interaction and authentication limits the attack scope but does not eliminate the risk, particularly in environments where phishing or social engineering is feasible. Compromise of pfSense management interfaces could disrupt network security posture, leading to broader impacts on availability and integrity if attackers manipulate firewall rules or IDS configurations. Given the critical role of pfSense in many small to medium enterprises and some public sector networks across Europe, the vulnerability could be leveraged in targeted campaigns against strategic infrastructure or high-value organizations.

1. Apply official patches or updates from Netgate as soon as they become available to address the input sanitization issue in suricata_filecheck.php. 2. Until patches are released, restrict access to the pfSense web interface to trusted networks and IP addresses using firewall rules or VPNs to minimize exposure. 3. Implement strict Content Security Policy (CSP) headers on the pfSense web interface to limit the execution of injected scripts. 4. Educate network administrators and users about the risks of clicking on unsolicited or suspicious links, especially those targeting the pfSense management interface. 5. Regularly monitor pfSense logs for unusual activity or access patterns that could indicate exploitation attempts. 6. Consider disabling Suricata integration or the vulnerable web page if not essential, reducing the attack surface. 7. Employ multi-factor authentication (MFA) on the pfSense web interface to reduce the risk of session hijacking. 8. Conduct periodic security assessments and penetration tests focusing on web interface vulnerabilities to detect similar issues proactively.