CVE-2024-43042: Pluck CMS Auth Bypass Vulnerability

CVE-2024-43042 Overview

Pluck CMS 4.7.18 contains a critical authentication vulnerability where the application does not restrict failed login attempts. This security flaw allows attackers to execute brute force attacks against the login mechanism, potentially gaining unauthorized access to administrative accounts and compromising the entire content management system.

Critical Impact

Attackers can conduct unlimited brute force attacks against Pluck CMS login pages, potentially compromising administrator accounts and gaining full control over website content and server resources.

Affected Products

• Pluck CMS version 4.7.18
• pluck-cms pluck

Discovery Timeline

• 2024-08-16 - CVE-2024-43042 published to NVD
• 2025-03-19 - Last updated in NVD database

Technical Details for CVE-2024-43042

Vulnerability Analysis

This vulnerability falls under CWE-307: Improper Restriction of Excessive Authentication Attempts. The Pluck CMS authentication mechanism lacks proper rate limiting and account lockout controls, creating a significant security weakness. Without these protections, the login form accepts an unlimited number of authentication attempts without triggering any defensive measures such as account lockouts, CAPTCHA challenges, or progressive delays.

The absence of brute force protection is particularly concerning for content management systems, which often hold sensitive data and provide administrative access to web server resources. An attacker with network access can systematically test password combinations against known usernames until valid credentials are discovered.

Root Cause

The root cause of this vulnerability is the missing implementation of authentication attempt throttling in Pluck CMS 4.7.18. The login handler processes each authentication request independently without tracking failed attempts per user account or source IP address. This design oversight means no mechanisms exist to detect and block suspicious authentication patterns characteristic of brute force attacks.

Attack Vector

The attack vector for CVE-2024-43042 is network-based, requiring no privileges or user interaction. An attacker can target the Pluck CMS login page remotely using automated tools to rapidly submit credential combinations. Common attack scenarios include:

• Dictionary attacks: Testing common passwords against administrator accounts
• Credential stuffing: Using leaked username/password pairs from other breaches
• Hybrid attacks: Combining dictionary words with common patterns and substitutions

The vulnerability manifests in the login authentication flow where failed attempts are not tracked or limited. Without rate limiting controls, attackers can submit thousands of login requests per minute using automated tools such as Hydra, Burp Suite Intruder, or custom scripts. For technical details regarding the vulnerability, refer to the Pluck CMS GitHub repository and the associated documentation.

Detection Methods for CVE-2024-43042

Indicators of Compromise

• High volume of failed login attempts from single or multiple IP addresses in web server access logs
• Unusually rapid POST requests to the Pluck CMS login endpoint
• Successful login events following numerous failed authentication attempts
• Login attempts using common username patterns such as admin, administrator, or root

Detection Strategies

• Monitor web server logs for anomalous authentication patterns including failed login spikes
• Implement Web Application Firewall (WAF) rules to detect and alert on brute force behavior
• Deploy intrusion detection systems (IDS) with signatures for HTTP-based credential attacks
• Use SIEM correlation rules to identify distributed brute force attempts across multiple source IPs

Monitoring Recommendations

• Configure real-time alerting for authentication failures exceeding baseline thresholds
• Enable detailed logging for the Pluck CMS authentication module
• Track unique source IP addresses attempting authentication against admin endpoints
• Monitor for successful logins from previously untrusted IP addresses following failed attempt patterns

How to Mitigate CVE-2024-43042

Immediate Actions Required

• Implement rate limiting at the web server or reverse proxy level to restrict login attempts
• Deploy a Web Application Firewall (WAF) with brute force protection rules
• Use strong, unique passwords for all Pluck CMS administrator accounts
• Consider IP whitelisting for administrative access where feasible
• Enable multi-factor authentication (MFA) if supported by plugins or external modules

Patch Information

As of the last modification date (2025-03-19), check the Pluck CMS GitHub repository for updated versions that address this vulnerability. Review vendor communications for official patches or security updates. Until an official patch is available, implement the workarounds and compensating controls described below.

Workarounds

• Configure web server rate limiting using modules such as mod_evasive (Apache) or limit_req (Nginx)
• Implement fail2ban or similar tools to automatically block IPs after failed login thresholds
• Add CAPTCHA protection to the login page using third-party plugins
• Restrict access to the admin login page by IP address using .htaccess or firewall rules
• Consider placing the CMS behind a VPN for administrative access

# Nginx rate limiting configuration example for login protection
limit_req_zone $binary_remote_addr zone=login:10m rate=5r/m;

location /login.php {
    limit_req zone=login burst=3 nodelay;
    # Additional location directives
}