CVE-2018-0101: A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA) Software could allow an unauthentic...

Description

A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a reload of the affected system or to remotely execute code. The vulnerability is due to an attempt to double free a region of memory when the webvpn feature is enabled on the Cisco ASA device. An attacker could exploit this vulnerability by sending multiple, crafted XML packets to a webvpn-configured interface on the affected system. An exploit could allow the attacker to execute arbitrary code and obtain full control of the system, or cause a reload of the affected device. This vulnerability affects Cisco ASA Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (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, ASA 1000V Cloud Firewall, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4110 Security Appliance, Firepower 9300 ASA Security Module, Firepower Threat Defense Software (FTD). Cisco Bug IDs: CSCvg35618.

Metrics

EPSS Probability

87.40%

99.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Adaptive Security Appliance Software	< 9.1.7.23
Cisco	Adaptive Security Appliance Software	>= 9.2.0, < 9.2.4.27
Cisco	Adaptive Security Appliance Software	>= 9.3.0, < 9.4.4.16
Cisco	Adaptive Security Appliance Software	>= 9.5.0, < 9.6.4.3
Cisco	Adaptive Security Appliance Software	>= 9.7.0, < 9.7.1.21
Cisco	Adaptive Security Appliance Software	>= 9.8.0, < 9.8.2.20
Cisco	Adaptive Security Appliance Software	>= 9.9.0, < 9.9.1.2
Cisco	Firepower Threat Defense	6.0.0
Cisco	Firepower Threat Defense	6.0.1
Cisco	Firepower Threat Defense	6.1.0
Cisco	Firepower Threat Defense	6.2.0
Cisco	Firepower Threat Defense	6.2.1
Cisco	Firepower Threat Defense	6.2.2

References

http://www.securityfocus.com/bid/102845Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040292Third Party Advisory, VDB Entry
https://icanthackit.wordpress.com/2018/01/30/thoughts-on-the-handling-cve-2018-0101-cisco-bug-cscvg35618/Third Party Advisory
https://pastebin.com/YrBcG2LnExploit, Third Party Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180129-asa1Vendor Advisory
https://www.exploit-db.com/exploits/43986/Exploit, Third Party Advisory, VDB Entry
http://www.securityfocus.com/bid/102845Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040292Third Party Advisory, VDB Entry
https://icanthackit.wordpress.com/2018/01/30/thoughts-on-the-handling-cve-2018-0101-cisco-bug-cscvg35618/Third Party Advisory
https://pastebin.com/YrBcG2LnExploit, Third Party Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180129-asa1Vendor Advisory
https://www.exploit-db.com/exploits/43986/Exploit, Third Party Advisory, VDB Entry

Timeline

Published: Jan 29, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-0101?

A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a reload of the affected system or to remotely execute code. The vulnerability is due to an attempt to double free a region of memory when the webvpn feature is enabled on the Cisco ASA device. An attacker could exploit this vulnerability by sending multiple, crafted XML packets to a webvpn-configured interface on the affected system. An exploit could allow the attacker to execute arbitrary code and obtain full control of the system, or cause a reload of the affected device. This vulnerability affects Cisco ASA Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (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, ASA 1000V Cloud Firewall, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4110 Security Appliance, Firepower 9300 ASA Security Module, Firepower Threat Defense Software (FTD). Cisco Bug IDs: CSCvg35618.

How severe is CVE-2018-0101?

Severity scoring for CVE-2018-0101 is pending analysis. The EPSS model estimates a 87.40% probability of exploitation in the next 30 days.

How do I fix CVE-2018-0101?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.