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.
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
CVE Number – CVE-2018-0101
This advisory is available at the following link:
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)
This vulnerability affects devices that are running a vulnerable release of Cisco ASA Software where the webvpn feature is enabled. In addition to webvpn being globally configured there must be one enabled interface via the enable <if_name> in the configuration. To determine whether webvpn is enabled for at least one interface, administrators can use the show running-config webvpn command at the CLI and verify that the command returns at least one enable <if_name> line.
8.x Migrate to 184.108.40.206 or later
9.0 Migrate to 220.127.116.11 or later
9.1 Migrate to 18.104.22.168 or later
9.2 Migrate to 22.214.171.124 or later
9.3 Migrate to 126.96.36.199 or later
9.4 Migrate to 188.8.131.52 or later
9.5 Migrate to 184.108.40.206 or later
9.6 Migrate to 220.127.116.11 or later
9.7 Migrate to 18.104.22.168 or later
9.8 Migrate to 22.214.171.124 or later
9.9 Migrate to 126.96.36.199 or later
Duncan is a technology professional with over 20 years experience of working in various IT roles. He has a interest in cyber security, and has a wide range of other skills in radio, electronics and telecommunications.