CVE-2026-41688 Wallos SSRF漏洞(DNS重绑定)

# Conceptual PoC demonstrating the DNS Rebinding attack vector # Attacker needs to control the DNS server for 'evil.com' import socket import time # Simulation of the vulnerable backend logic def vulnerable_backend_logic(target_domain): print(f"[Backend] Processing webhook for: {target_domain}") # Step 1: Time-of-Check (TOC) # Using gethostbyname() to validate the IP try: initial_ip = socket.gethostbyname(target_domain) print(f"[Backend] Validation check: {target_domain} resolves to {initial_ip}") # Check if IP is private (simplified check) if initial_ip.startswith("127.") or initial_ip.startswith("192.168."): print("[Backend] Validation Failed: Private IP detected.") return print("[Backend] Validation Passed: Public IP allowed.") except socket.gaierror: print("[Backend] DNS resolution failed.") return # TIMING WINDOW: Attacker switches DNS record here (e.g., to 127.0.0.1) # In a real attack, this is where the race condition happens. print("[Simulated Delay] ... Attacker switches DNS record ...") time.sleep(1) # Forcing a delay to simulate the gap # Step 2: Time-of-Use (TOU) # Vulnerable code passes 'target_domain' to cURL without CURLOPT_RESOLVE # Here we simulate the cURL request by resolving again try: # In the real vulnerability, cURL might resolve again or use a different cache final_ip = socket.gethostbyname(target_domain) print(f"[Backend] cURL Request sent to: {final_ip}") if final_ip != initial_ip: print(f"[EXPLOIT SUCCESS] DNS Rebinding occurred! Request hit {final_ip} instead of {initial_ip}") else: print("[Safe] IP remained consistent.") except socket.gaierror: print("[Backend] DNS resolution failed during request.") # To test this, one would need to manipulate the local hosts file or run a custom DNS server # that changes the response between the two gethostbyname calls. if __name__ == "__main__": # This is a demonstration of the logic gap, not a functional exploit against a live target # without a controlled DNS environment. pass