CVE-2024-8005: Demozx Gf Cms Auth Bypass Vulnerability

CVE-2024-8005 Overview

A critical vulnerability has been identified in demozx gf_cms versions 1.0 and 1.0.1, affecting the JWT authentication component. The vulnerability exists within the init function of the file internal/logic/auth/auth.go, where hard-coded credentials are used for JWT token generation and validation. This security flaw allows remote attackers to bypass authentication mechanisms and potentially gain unauthorized access to the content management system.

Critical Impact

Remote attackers can exploit hard-coded JWT credentials to forge authentication tokens, bypass security controls, and gain unauthorized access to the gf_cms application without valid credentials.

Affected Products

• demozx gf_cms version 1.0
• demozx gf_cms version 1.0.1

Discovery Timeline

• August 20, 2024 - CVE-2024-8005 published to NVD
• August 21, 2024 - Last updated in NVD database

Technical Details for CVE-2024-8005

Vulnerability Analysis

This vulnerability falls under CWE-798 (Use of Hard-Coded Credentials), a configuration and design flaw that poses significant security risks in production environments. The gf_cms application implemented JWT authentication using a predictable, hard-coded secret key within the authentication logic. When JWT tokens are signed with a known or predictable key, attackers can forge valid authentication tokens without knowing legitimate user credentials.

The vulnerability is remotely exploitable over the network without requiring any authentication or user interaction. An attacker who discovers or guesses the hard-coded JWT key can craft arbitrary authentication tokens, effectively impersonating any user including administrative accounts.

Root Cause

The root cause of this vulnerability lies in the improper implementation of JWT secret key management in the internal/logic/auth/auth.go file. Instead of utilizing a configurable, cryptographically random secret key, the application relied on a hard-coded or easily predictable value for signing and verifying JWT tokens. This represents a fundamental security design flaw where sensitive cryptographic material was embedded directly in the source code rather than being externalized to secure configuration.

Attack Vector

The attack vector is network-based, allowing remote exploitation. An attacker can exploit this vulnerability by:

1. Analyzing the source code or reverse-engineering the application to discover the hard-coded JWT secret
2. Crafting a forged JWT token with arbitrary claims (user ID, role, permissions)
3. Submitting the forged token to authenticated API endpoints
4. Gaining unauthorized access to protected resources and administrative functions

The security patch introduces a new configurable server.jwtKey setting, removing the reliance on hard-coded values:

// JwtKey 获取JwtKey
func (*sUtil) JwtKey() string {
	jwtKey := Util().GetConfig("server.jwtKey")
	if jwtKey == "" {
		return ProjectName.String()
	}
	return jwtKey
}

Source: GitHub Commit be702ada

The patch also updates the authentication logic to use the new configurable JWT key:

import (
	"context"
	"gf_cms/internal/logic/admin"
+	"gf_cms/internal/logic/util"
	"gf_cms/internal/model"
	"gf_cms/internal/service"
	"time"

Source: GitHub Commit de51cc57

Detection Methods for CVE-2024-8005

Indicators of Compromise

• Unexpected or unauthorized administrative sessions in gf_cms access logs
• JWT tokens with unusual claims or timestamps that don't match legitimate user activity
• Authentication events from IP addresses not associated with legitimate users
• Spike in API requests to protected endpoints without corresponding login events

Detection Strategies

• Review application access logs for authentication anomalies and unexpected privileged operations
• Implement JWT token validation logging to track token usage patterns
• Monitor for requests containing JWT tokens with suspicious or forged claims
• Deploy web application firewalls (WAF) with rules to detect authentication bypass attempts

Monitoring Recommendations

• Enable comprehensive logging for all authentication-related endpoints in gf_cms
• Set up alerts for multiple failed authentication attempts followed by successful access
• Monitor for changes to user permissions or creation of new administrative accounts
• Implement real-time monitoring of JWT token generation and validation events

How to Mitigate CVE-2024-8005

Immediate Actions Required

• Upgrade demozx gf_cms to version 1.0.2 or later immediately
• Configure a strong, unique server.jwtKey value in the application configuration
• Invalidate all existing JWT tokens by rotating the JWT secret key
• Review access logs for signs of unauthorized access during the vulnerability window

Patch Information

The vulnerability has been addressed in gf_cms version 1.0.2. The fix is contained in commit be702ada7cb6fdabc02689d90b38139c827458a5, which introduces a configurable server.jwtKey option. Organizations running affected versions should upgrade immediately by pulling the latest release from the official repository. For detailed information about the vulnerability and patch, refer to the GitHub Issue Discussion.

Workarounds

• If immediate upgrade is not possible, restrict network access to the gf_cms application to trusted IP ranges only
• Implement additional authentication layers such as IP whitelisting or VPN requirements
• Deploy a reverse proxy with additional authentication controls in front of the application
• Monitor all access attempts closely until the patch can be applied

# Configuration example - Add to your gf_cms server configuration
# Set a strong, unique JWT key (minimum 32 characters recommended)
server:
  jwtKey: "your-unique-cryptographically-strong-secret-key-here"