{"cve":"CVE-2018-0227","nvd":{"published":"2018-04-19T20:29:00.300","modified":"2026-08-11T19:37:30.880","status":"Modified","description":"A vulnerability in the Secure Sockets Layer (SSL) Virtual Private Network (VPN) Client Certificate Authentication feature for Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to establish an SSL VPN connection and bypass certain SSL certificate verification steps. The vulnerability is due to incorrect verification of the SSL Client Certificate. An attacker could exploit this vulnerability by connecting to the ASA VPN without a proper private key and certificate pair. A successful exploit could allow the attacker to establish an SSL VPN connection to the ASA when the connection should have been rejected. This vulnerability affects Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) Software that is running on the following Cisco products: 3000 Series Industrial Security Appliances (ISA), ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliances (ASAv), Firepower 4110 Security Appliances, Firepower 9300 ASA Security Modules. Cisco Bug IDs: CSCvg40155.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-295"],"references":["http://www.securityfocus.com/bid/104018","http://www.securitytracker.com/id/1040723","https://ics-cert.us-cert.gov/advisories/ICSA-18-184-01","https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180418-asa1","http://www.securityfocus.com/bid/104018"],"products":["cisco:adaptive_security_appliance_software","cisco:secure_firewall_threat_defense"],"source":"nvd","synced_at":"2026-10-19T20:49:59.483420567+00:00"},"epss":{"cve":"CVE-2018-0227","score":0.0205,"percentile":0.81243,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}