CVE-2025-62709 is a medium-severity vulnerability affecting ClipBucket version 5.5.2, an open-source video sharing platform. The root cause is the dynamic construction of the server URL for password reset links from the HTTP Host header when the base_url configuration parameter is not set. Since the Host header is client-controlled, an attacker can supply an arbitrary domain name. Consequently, password reset emails generated by forget.php include links pointing to attacker-controlled domains. When a victim clicks such a link and inputs their activation code on the malicious domain, the attacker intercepts the code. This code can then be used to reset the victim’s password, enabling account takeover without requiring authentication. The vulnerability is categorized under CWE-640 (Weak Password Recovery Mechanism). Exploitation requires user interaction (victim clicking the malicious link and entering the code) but no prior authentication or elevated privileges. The issue was addressed in ClipBucket version 5.5.2#162 by fixing the URL generation logic to avoid reliance on the Host header or by enforcing a fixed base_url. No known exploits are reported in the wild as of the publication date. The CVSS 3.1 vector (AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N) indicates network attack vector, high attack complexity, no privileges required, user interaction needed, unchanged scope, and high impact on confidentiality and integrity but no impact on availability.

For European organizations deploying ClipBucket v5.5.2 without the patch or proper configuration, this vulnerability poses a significant risk of account takeover. Attackers can hijack user accounts by intercepting password reset codes, potentially gaining unauthorized access to sensitive user data, administrative functions, or content management capabilities. This can lead to data breaches, defacement or unauthorized content uploads, and reputational damage. Organizations with public-facing video sharing platforms or community portals are particularly vulnerable. The impact is heightened for entities handling personal data subject to GDPR, as unauthorized access could lead to regulatory penalties. Additionally, compromised accounts could be leveraged for further lateral attacks or phishing campaigns targeting European users. The requirement for user interaction limits automated exploitation but social engineering can facilitate attacks. The medium severity rating reflects the balance between impactful consequences and the need for user involvement.

1. Immediately upgrade ClipBucket installations to version 5.5.2#162 or later, where the vulnerability is patched. 2. Explicitly set the base_url configuration parameter in ClipBucket to a fixed, trusted domain to prevent reliance on the HTTP Host header for URL generation. 3. Implement monitoring and alerting on password reset requests and email contents to detect anomalies such as unexpected domains in reset links. 4. Educate users about phishing risks and advise them to verify URLs in password reset emails before entering activation codes. 5. Employ email security measures such as DMARC, DKIM, and SPF to reduce the risk of email spoofing that could facilitate this attack. 6. Consider adding multi-factor authentication (MFA) to user accounts to mitigate the impact of password resets being compromised. 7. Review and harden web server configurations to reject suspicious or malformed Host headers where possible. 8. Conduct regular security audits and penetration tests focusing on password recovery workflows.