CVE-2025-62709: Critical Password Reset Vulnerability in ClipBucket v5

Overview

CVE-2025-62709 describes a medium-severity vulnerability affecting ClipBucket v5, an open-source video sharing platform. Specifically, versions up to and including 5.5.2 are susceptible. This flaw allows attackers to craft malicious password reset links by manipulating the HTTP Host header. By tricking users into clicking these links and entering their activation code, attackers can compromise user accounts.

Technical Details

The vulnerability lies in how ClipBucket dynamically constructs the server URL when the base_url configuration is not explicitly set. The application uses the incoming HTTP Host header to build this URL. Since the Host header is client-controlled, an attacker can inject an arbitrary domain. This allows them to forge password reset links (generated through forget.php) that point to the attacker’s malicious server.

Here’s the flow of the attack:

1. Attacker requests a password reset for a victim user.
2. ClipBucket generates a password reset link using the attacker-controlled Host header.
3. The crafted password reset link is sent to the victim’s email.
4. The victim, unaware of the malicious URL, clicks the link.
5. The victim is redirected to the attacker’s server, which mimics the ClipBucket password reset page.
6. The victim enters their activation code on the attacker’s page.
7. The attacker captures the activation code.
8. The attacker uses the activation code to reset the victim’s password and gain control of their account.

The problematic code resides in network.class.php. The fix can be viewed in the commit referenced below.

CVSS Analysis

This vulnerability has been assigned a CVSS score of 6.8, indicating a MEDIUM severity. The CVSS vector is likely something like AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N, reflecting the network attack vector, low attack complexity, no privileges required, user interaction required, unchanged scope, limited confidentiality impact, limited integrity impact, and no availability impact.

Possible Impact

Successful exploitation of this vulnerability can lead to:

• Account Takeover: Attackers can gain complete control of user accounts, potentially accessing sensitive data and performing actions on behalf of the victim.
• Reputation Damage: A successful attack can damage the reputation of the ClipBucket platform and any websites using it.
• Data Breach: Depending on the privileges associated with the compromised account, attackers may be able to access and exfiltrate sensitive data.

Mitigation or Patch Steps

The vulnerability has been patched in ClipBucket version 5.5.2#162. It is strongly recommended to upgrade to this version or a later version immediately. If upgrading is not immediately possible, consider implementing a temporary workaround, such as:

• Setting the base_url configuration: Explicitly set the base_url in your ClipBucket configuration to prevent the application from dynamically building the URL from the Host header.
• Implementing a web server rule: Implement a web server rule (e.g., in Apache or Nginx) to sanitize or validate the Host header.

References

• Commit Patching the Vulnerability
• GitHub Security Advisory