CVE-2025-67418

Executive Summary

CVE-2025-67418 is a critical vulnerability in ClipBucket 5.5.2, a popular open-source video sharing platform. The issue stems from the application being shipped or deployed with hardcoded default administrative credentials. An unauthenticated remote attacker can exploit this by simply logging into the administrative panel using these well-known default credentials, thereby gaining full administrative control over the application. This includes the ability to modify site content, access user data, execute arbitrary code via plugin uploads, and potentially pivot to the underlying server.

The vulnerability is classified under CWE-798 (Use of Hard-coded Credentials) and is mapped to MITRE ATT&CK tactic T1190 (Exploit Public-Facing Application). The CVSS v3.1 base score is 9.8 (Critical), reflecting the ease of exploitation and the high impact on confidentiality, integrity, and availability.

Supply Chain & Package Security

ClipBucket is a PHP-based application. While this specific vulnerability is not a direct supply chain compromise of a package manager (like NPM or PyPI), the risk is amplified if the application is deployed via container images or automated scripts that include the default credentials. Organizations should verify that any ClipBucket deployment does not originate from an untrusted source that might have pre-configured these credentials.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• Base Score: 9.8 (Critical)
• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component and the impacted component are the same.
• Confidentiality (C): High (H) – Full read access to all application data.
• Integrity (I): High (H) – Full write access to application data and configuration.
• Availability (A): High (H) – Ability to disrupt service or delete data.

Threat Level: Critical. The combination of remote exploitability, no authentication requirement, and full administrative access makes this a top-priority vulnerability for any organization using ClipBucket 5.5.2.

Deep Dive & Mechanics

The vulnerability is a classic case of hardcoded credentials. ClipBucket 5.5.2 includes a default administrator account (e.g., username: admin, password: admin or similar) that is not changed during the installation process. The authentication mechanism in the administrative panel (/admin_area/) does not enforce a password change on first login, nor does it check if the default credentials have been altered.

The attack flow is straightforward:

1. An attacker identifies a ClipBucket 5.5.2 instance (e.g., via Shodan or Google dorking).
2. The attacker navigates to the admin login page (typically /admin_area/login.php or /admin/).
3. The attacker attempts to log in using the known default credentials (e.g., admin:admin, admin:clipbucket, administrator:password).
4. Upon successful authentication, the attacker gains full access to the admin panel.

Once inside, the attacker can:

• Upload malicious plugins or themes (PHP files) to achieve remote code execution.
• Modify user roles and permissions.
• Access and exfiltrate the database (user data, videos, etc.).
• Deface the website or inject malicious content.
• Use the server as a pivot point for further attacks.

Vulnerable vs. Patched Code

Since no official patch is available, the "patched" state is defined by the absence of hardcoded credentials.

Vulnerable Code (ClipBucket 5.5.2 - includes/classes/ClipBucket.class.php or similar):

// Example of hardcoded credential check (simplified)
$default_admin = array(
    'username' => 'admin',
    'password' => md5('admin') // or plaintext
);

if ($_POST['username'] == $default_admin['username'] && md5($_POST['password']) == $default_admin['password']) {
    // Grant admin access
}

Patched Code (Recommended Fix):

// Remove hardcoded credentials entirely
// Ensure the admin user is created during installation with a forced password change
// Example: Check if the admin user exists and has a non-default password
$admin_user = $db->select(tbl('users'), array('username' => 'admin'));
if ($admin_user && $admin_user['password'] == md5('admin')) {
    // Force password change
    header('Location: /admin_area/change_password.php');
    exit();
}

The patched version should:

1. Not ship with any pre-defined credentials.
2. Force the administrator to set a strong password during the initial setup.
3. Implement a check that prevents login if the password matches any known default hash.

Exploitation & Lab Setup

Red Team (Exploitation)

Lab Setup:

1. Deploy ClipBucket 5.5.2 on a local server (e.g., using Docker or a LAMP stack).
2. Ensure the default installation is complete.

Exploitation Steps:

1. Identify the admin login URL (e.g., http://target/admin_area/login.php).
2. Use a tool like curl or a Python script to attempt login with default credentials.

Example using curl:

curl -X POST http://target/admin_area/login.php \
  -d "username=admin&password=admin" \
  -c cookies.txt -L

Example Python Script:

import requests

target = "http://target/admin_area/login.php"
credentials = {"username": "admin", "password": "admin"}

session = requests.Session()
response = session.post(target, data=credentials)

if "admin_area" in response.url or "dashboard" in response.text:
    print("[+] Admin access granted!")
else:
    print("[-] Login failed.")

Post-Exploitation:

• Upload a malicious plugin (PHP web shell) via the admin panel's plugin manager.
• Access the web shell to execute system commands.

Blue Team (Detection & Response)

Detection Steps:

1. Monitor authentication logs for successful logins from the admin account, especially from unexpected IP addresses.
2. Look for rapid login attempts using common default usernames (admin, administrator, root).
3. Check for unusual admin panel activity, such as plugin uploads or user role changes.

Hunting Query (Splunk):

index=web_logs sourcetype=access_combined
| search uri_path="/admin_area/login.php" AND form_data="username=admin"
| stats count by src_ip, user_agent, status
| where status=200

Indicators of Compromise (IOCs)

• Network IOCs:

  • POST requests to /admin_area/login.php with username=admin and password=admin (or similar).
  • Subsequent POST requests to /admin_area/plugin_upload.php or /admin_area/theme_upload.php.
  • Outbound connections from the web server to unknown IPs (potential C2).

• File System IOCs:

  • Unexpected PHP files in /plugins/ or /themes/ directories.
  • Modified .htaccess files.
  • New user accounts in the database with admin privileges.

• Log IOCs:

  • Successful login events for the admin user from unusual IPs.
  • Error logs showing attempts to access non-existent admin pages.

Detection Engineering

YARA Rule

rule CVE_2025_67418_ClipBucket_Default_Creds {
    meta:
        description = "Detects ClipBucket 5.5.2 files with hardcoded default admin credentials"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-67418"
    strings:
        $cred1 = "admin" ascii wide nocase
        $cred2 = "password" ascii wide nocase
        $cred3 = "clipbucket" ascii wide nocase
        $php_func = "md5" ascii wide
    condition:
        all of ($cred*) and $php_func
}

Sigma Rule

title: ClipBucket Default Admin Login Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects login attempts using default admin credentials for ClipBucket 5.5.2
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/admin_area/login.php'
        cs-uri-query|contains: 'username=admin'
    condition: selection
falsepositives:
    - Legitimate admin login if password was changed
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-67418 ClipBucket Default Admin Login Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/admin_area/login.php"; http_uri;
    content:"username=admin"; http_client_body;
    content:"password=admin"; http_client_body;
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Change Default Credentials: Log in to the admin panel and immediately change the password for the default admin account. If the default account cannot be changed, create a new admin account and delete the default one.
2. Disable Default Account: If possible, disable or rename the default admin user.
3. Network Segmentation: Restrict access to the admin panel to trusted IP addresses only (e.g., via .htaccess or firewall rules).
4. Web Application Firewall (WAF): Deploy a WAF rule to block login attempts using known default credentials.

Long-Term Fixes:

• Patch Application: Monitor the ClipBucket project for an official patch. If none is released, consider forking the code and implementing the fix described in the "Vulnerable vs. Patched Code" section.
• Code Review: Conduct a security audit of the authentication mechanism to ensure no other hardcoded credentials exist.
• User Education: Ensure all administrators understand the importance of changing default credentials immediately after installation.

Valters IT Signature This report was generated by Valters IT DevSecOps AI. For questions, contact security@valters-it.com.