CVE-2025-63520 identifies a Cross Site Scripting (XSS) vulnerability in FeehiCMS version 2.1.1, specifically through the 'id' parameter in the User Update function endpoint (?r=user%2Fupdate). XSS vulnerabilities occur when untrusted input is improperly sanitized and then rendered in a web page, allowing attackers to inject malicious scripts that execute in the victim's browser. This vulnerability is classified under CWE-79, indicating improper neutralization of input during web page generation. The attack vector is network-based (AV:N), requiring no privileges (PR:N), but does require user interaction (UI:R), such as clicking a maliciously crafted URL. The scope is changed (S:C), meaning the vulnerability can affect resources beyond the initially vulnerable component. The impact affects confidentiality and integrity at a low level (C:L/I:L) but does not affect availability (A:N). The CVSS score of 6.1 reflects a medium severity level. No patches or known exploits are currently reported, but the vulnerability poses a risk of session hijacking, credential theft, or unauthorized actions performed in the context of the victim user. FeehiCMS is a content management system used primarily in some Asian markets but also by niche users worldwide, including Europe. The vulnerability's exploitation could lead to compromised user accounts and unauthorized data access if exploited successfully.

For European organizations using FeehiCMS 2.1.1, this vulnerability could lead to unauthorized access to user accounts and sensitive information through session hijacking or theft of authentication tokens. Although the impact on availability is none, the confidentiality and integrity of user data could be compromised, potentially leading to data breaches or unauthorized changes to user profiles. Organizations relying on FeehiCMS for public-facing websites or internal portals may face reputational damage and compliance issues if user data is exposed. The requirement for user interaction limits the ease of exploitation but does not eliminate risk, especially in phishing-prone environments. The medium severity suggests that while the threat is not critical, it should be addressed promptly to avoid escalation or chaining with other vulnerabilities.

1. Immediately apply any available patches or updates from FeehiCMS developers once released. 2. Implement strict input validation and sanitization on the 'id' parameter in the User Update function to neutralize malicious scripts. 3. Employ output encoding techniques to ensure that user-supplied data is safely rendered in HTML contexts. 4. Use Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 5. Educate users about the risks of clicking on suspicious links, especially those that appear to interact with user update functions. 6. Monitor web application logs for unusual requests targeting the vulnerable endpoint. 7. Consider deploying Web Application Firewalls (WAFs) with rules to detect and block XSS payloads targeting FeehiCMS. 8. Conduct regular security assessments and penetration testing focusing on input validation and XSS vulnerabilities.