Executive Summary

CVE ID: CVE-2025–67418 Vulnerability Type: Improper Access Control Affected Product: ClipBucket Affected Versions: 5.0 to 5.5.2 Attack Vector: Remote Severity: Critical Impact: Full Administrative Takeover, Data Exposure, System Compromise

ClipBucket versions 5.0 through 5.5.2 ship with default administrative credentials that remain active after installation. The application does not enforce credential rotation or secure initialization, allowing any remote attacker to authenticate directly to the administrative panel and obtain full control of the application.

This vulnerability turns a fresh deployment into an immediately compromised system.

The Core Problem

Authentication exists. Authorization exists. Yet security still fails.

Why? Because the most privileged account in the system is exposed by default.

ClipBucket does not require administrators to change default credentials during installation or first login. As a result, the highest-privilege account remains accessible to anyone who knows the defaults.

No exploit. No bypass. No brute force.

Just logging in as designed.

The Attack Chain

Privilege Escalation Pipeline

Unauthenticated Remote User → Access Admin Login Page → Authenticate Using Default Credentials → Administrative Session Granted → Full System Control Achieved

This is not an edge case. This is the default behavior.

Why This Vulnerability Is Critical

Zero-Effort Exploitation No tools, no payloads, no special conditions required.

Immediate Privilege Escalation Anonymous user to full administrator in one step.

Remote and Scalable Any exposed instance is vulnerable.

Complete Impact Surface Administrative access enables data access, configuration changes, file uploads, and potential code execution.

This vulnerability collapses the entire trust model of the application.

Technical Analysis

Root Cause

The vulnerability originates from a failure in secure initialization and access control enforcement.

1. Hardcoded Default Credentials

  • Administrative credentials are shipped with the product
  • Credentials remain valid post-installation
  • No expiration or forced rotation

2. Missing First-Run Security Enforcement

  • No mandatory password change
  • No setup hardening phase
  • No warnings for unchanged defaults

3. Full Privilege Binding

Once authenticated, the default administrative account receives unrestricted access across the platform.

There is no secondary verification, role validation, or conditional access.

Proof of Concept Overview

A remote user navigates to the ClipBucket administrative login interface and authenticates using default credentials supplied with the software. Upon successful login, the user gains unrestricted administrative access.

No security controls are bypassed. The system behaves exactly as implemented.

Impact Assessment

Successful exploitation allows:

  • Full administrative dashboard access
  • User account management and data access
  • Application configuration modification
  • Media and file upload capabilities
  • Potential remote code execution paths
  • Complete loss of confidentiality and integrity

From a risk perspective, this is equivalent to handing over the application keys to the internet.

Why This Happens in Real Deployments

Default credentials are often overlooked during setup, especially in:

  • Quick deployments
  • Test environments promoted to production
  • Self-hosted or unmanaged installations
  • Administrators unfamiliar with security hardening

Attackers actively scan for exactly this condition.

Mitigation Strategy

Immediate Fixes

1. Eliminate Default Credentials

  • Do not ship active default credentials
  • Generate unique credentials per installation

2. Enforce Mandatory Credential Rotation

  • Require password change on first login
  • Block administrative access until completed

3. Secure Installation Workflow

  • Add a hardening step during setup
  • Prevent application use until security initialization is complete

Defense-in-Depth Improvements

  • Restrict administrative panel access by IP
  • Implement login anomaly detection
  • Add warnings for weak or default credentials
  • Log and alert on first administrative access

Lessons Learned

For Developers

  • Authentication without secure initialization is not security
  • Default credentials are a vulnerability, not a convenience
  • Administrative accounts require stricter lifecycle controls

For Security Teams

  • Check for default credentials during assessments
  • Treat administrative interfaces as externally hostile surfaces
  • Include configuration flaws in threat modeling

For Product Architects

  • Secure defaults are non-negotiable
  • First-run security must be enforced, not suggested
  • Assume exposed deployments will be attacked

Researcher

Arpit Sharma Security Researcher and Bug Hunter