CVE-2025-62715 is a stored Cross-Site Scripting (XSS) vulnerability identified in MacWarrior's ClipBucket v5, specifically affecting versions 5.5.2-#147 and earlier. The vulnerability arises from improper neutralization of user input in the Collection tags feature, where authenticated normal users can insert HTML or JavaScript code into tags. These tags are later rendered without proper escaping on collection detail and tag-list pages, causing the injected script to execute in the browsers of any users who visit these pages. This flaw allows attackers to perform client-side attacks such as session hijacking, credential theft, or delivering malicious payloads to other users. The vulnerability does not require elevated privileges beyond normal user authentication but does require user interaction to view the affected pages. The CVSS 4.0 vector indicates network attack vector, low attack complexity, no privileges required, but user interaction is necessary, with low confidentiality and integrity impact and no availability impact, resulting in a medium severity score of 5.3. No public exploits have been reported yet, but the vulnerability is publicly disclosed and fixed in version 5.5.2-#152. The flaw stems from CWE-79, highlighting improper input sanitization during web page generation. Organizations running vulnerable versions of ClipBucket are at risk of client-side compromise through malicious scripts embedded in user-generated content.

For European organizations, the impact of this vulnerability can be significant, especially for those operating video sharing or content platforms using ClipBucket v5. Exploitation could lead to session hijacking, allowing attackers to impersonate legitimate users, potentially gaining unauthorized access to sensitive user data or administrative functions if sessions are reused. Credential theft via malicious scripts could facilitate broader compromise of user accounts. Additionally, attackers could use the vulnerability to deliver malware or phishing content to site visitors, damaging organizational reputation and user trust. While the vulnerability requires authenticated user input, many platforms allow open registration, increasing the risk of exploitation. The medium severity score reflects moderate risk, but the widespread use of ClipBucket in European web communities and educational or media organizations could amplify impact. Furthermore, regulatory frameworks like GDPR impose strict requirements on protecting user data, and exploitation leading to data breaches could result in legal and financial penalties. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers often develop exploits after public disclosure.

European organizations should immediately upgrade ClipBucket installations to version 5.5.2-#152 or later, where the vulnerability is patched. If immediate upgrading is not feasible, implement input validation and output encoding controls on the Collection tags feature to sanitize user input and escape HTML/JavaScript content before rendering. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. Limit user permissions to restrict who can create or modify tags, reducing the attack surface. Monitor logs for unusual tag creation activity or spikes in user-generated content submissions. Conduct regular security audits and penetration testing focusing on user input handling. Educate users and administrators about the risks of XSS and encourage reporting of suspicious behavior. Finally, ensure web application firewalls (WAFs) are configured to detect and block common XSS payloads targeting ClipBucket endpoints.