Cisco Adaptive Security Appliance Software
CVE-2018-0227
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.
What this means for your business
- It affects Cisco Adaptive Security Appliance Software. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 2% chance of attack attempts being seen in the next 30 days, ranking above 80% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Cisco Adaptive Security Appliance Software, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
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Scoring
- CVSS
- 7.5 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- Weakness
- CWE-295
- Assigned by
- psirt@cisco.com
Dates
- Published
- 2018-04-19
- Last modified
- 2026-08-11
- Sources
- NVD
Affected products
- Cisco Adaptive Security Appliance Software9.4.4 - 9.4.4.13, 9.5.3.7 - 9.5.3.9, 9.6.2.9 - 9.6.2.21, 9.6.3 - 9.6.3.17, 9.4.3.1, 9.4.3.2, 9.5.2.7, 9.5.2.8
- Cisco Secure Firewall Threat Defense6.0 - 6.0.1.4, 6.1.0 - 6.1.0.5
As listed in the NVD configuration data. Not a statement about your estate.
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
- 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