CVE-2025-66204 is a vulnerability classified under CWE-307 (Improper Restriction of Excessive Authentication Attempts) and CWE-693 (Protection Mechanism Failure) affecting WBCE CMS version 1.6.4. The core issue arises because the CMS fully trusts the X-Forwarded-For HTTP header to track the source IP address for brute-force protection purposes without validating or restricting its usage. Attackers can exploit this by sending login requests with a modified X-Forwarded-For header on each attempt, effectively resetting the failed login attempt counter indefinitely. This bypasses the intended brute-force protection mechanism, allowing unlimited password guessing attempts against user accounts. The vulnerability does not require prior authentication or user interaction, but the attack complexity is high because the attacker must continuously manipulate the header value. The flaw impacts confidentiality by increasing the risk of unauthorized access through credential guessing. The vulnerability was assigned a CVSS 4.0 score of 6.3 (medium severity), reflecting network attack vector, no privileges required, no user interaction, but high attack complexity and limited impact on confidentiality only. The issue was fixed in WBCE CMS version 1.6.5 by presumably validating or ignoring the X-Forwarded-For header for brute-force tracking. No known exploits have been reported in the wild as of the publication date. Organizations running vulnerable versions should upgrade promptly and consider additional mitigations such as multi-factor authentication and enhanced monitoring.

For European organizations using WBCE CMS version 1.6.4 or earlier, this vulnerability poses a significant risk of unauthorized access through brute-force attacks. Attackers can bypass rate-limiting protections by spoofing the X-Forwarded-For header, enabling unlimited password guessing attempts. This can lead to compromised user accounts, data breaches, and potential defacement or manipulation of web content managed by the CMS. The impact is particularly critical for organizations hosting sensitive or regulated data, such as government portals, healthcare providers, and financial institutions. Additionally, successful exploitation could undermine trust in affected services and lead to reputational damage. The medium severity rating reflects that while exploitation is not trivial, the consequences of unauthorized access can be substantial. The lack of known exploits in the wild suggests a window of opportunity for defenders to patch and mitigate before widespread attacks occur.

1. Upgrade WBCE CMS to version 1.6.5 or later immediately to apply the official fix that addresses the improper handling of the X-Forwarded-For header. 2. Implement multi-factor authentication (MFA) for all user accounts to reduce the risk posed by credential guessing. 3. Configure web application firewalls (WAFs) or reverse proxies to validate or sanitize the X-Forwarded-For header, ensuring it cannot be manipulated to bypass rate limiting. 4. Employ additional brute-force protection mechanisms that do not rely solely on client-supplied headers, such as tracking failed attempts by session or account rather than IP. 5. Monitor authentication logs for unusual patterns of login attempts with varying source IP addresses or header values. 6. Educate administrators and users on the importance of strong, unique passwords to reduce the risk of successful brute-force attacks. 7. Consider network-level rate limiting and anomaly detection to identify and block suspicious login behaviors. 8. Regularly audit CMS configurations and update software dependencies to minimize exposure to known vulnerabilities.