CVE-2025-63523 affects FeehiCMS version 2.1.1, a content management system, due to a failure in enforcing server-side immutability for parameters that are presented to clients as "read-only." This means that although certain parameters appear immutable on the client side, the backend does not validate or reject changes to these parameters when received. An attacker who can intercept network traffic (e.g., via a man-in-the-middle attack) can modify these parameters in transit. Specifically, this vulnerability allows an unauthenticated attacker to alter parameters that control usernames, resulting in unintended username changes on the server. This compromises the integrity of user account data, potentially enabling account takeover or privilege escalation if usernames are linked to authentication or authorization mechanisms. The vulnerability is remotely exploitable without requiring user interaction or privileges, increasing its risk profile. The CVSS v3.1 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N) indicates network attack vector, low attack complexity, no privileges or user interaction needed, unchanged scope, and low impact on confidentiality and integrity, with no impact on availability. No patches or known exploits are currently available, but the CWE-125 classification suggests an out-of-bounds read or similar memory handling issue related to parameter validation. Organizations using FeehiCMS 2.1.1 should be aware of this vulnerability and monitor for updates or mitigations.

For European organizations using FeehiCMS 2.1.1, this vulnerability poses a moderate risk primarily to data integrity. Unauthorized username changes can disrupt user management, potentially allowing attackers to impersonate legitimate users or escalate privileges if usernames are linked to access controls. This could lead to unauthorized access to sensitive information or administrative functions. The lack of authentication requirement and ease of exploitation over the network increase the threat surface, especially for organizations with public-facing FeehiCMS installations. While availability is not impacted, the integrity compromise could undermine trust in the CMS and lead to reputational damage. Organizations in sectors with strict data protection regulations, such as finance, healthcare, and government, may face compliance risks if user data integrity is compromised. The absence of known exploits reduces immediate risk but does not eliminate the potential for future attacks. Proactive mitigation is essential to prevent exploitation and maintain secure user management.

1. Immediately verify if your organization uses FeehiCMS version 2.1.1 and assess exposure, especially for public-facing web applications. 2. Monitor official FeehiCMS channels for patches or security updates addressing CVE-2025-63523 and apply them promptly once available. 3. Implement network-level protections such as enforcing HTTPS with strong TLS configurations to prevent interception and tampering of parameters in transit. 4. Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious parameter modifications related to usernames. 5. Conduct regular security audits and penetration testing focusing on parameter tampering and input validation weaknesses. 6. Where possible, implement server-side validation and immutability checks for critical parameters to reject unauthorized changes. 7. Educate development teams on secure coding practices to avoid similar issues in future CMS versions or custom modules. 8. Consider isolating or restricting access to administrative interfaces to trusted networks or VPNs to reduce exposure. 9. Maintain comprehensive logging and monitoring to detect anomalous username changes or access patterns. 10. Prepare incident response plans to quickly address potential exploitation scenarios involving user account manipulation.