CVE-2018-0101 remediation guide
Cisco Adaptive Security Appliance, adaptive security appliance software, secure firewall threat defense
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 c...
Identify the affected asset
Confirm whether Cisco Adaptive Security Appliance, adaptive security appliance software, secure firewall threat defense is installed, record the deployed version and installation path, and identify exposed interfaces.
- Record the product name, package or appliance identifier, and installed version.
- Identify internet-facing, administrative, API, and internal access paths.
- Preserve the pre-change configuration and relevant service logs.
Validate the affected-version match
Compare the deployed version with the affected range: >= Cisco Adaptive Security Appliance, < 9.1.7.23, >= 9.2.0 < 9.2.4.27, >= 9.3.0 < 9.4.4.16, >= 9.5.0 < 9.6.4.3, >= 9.7.0 < 9.7.1.21, >= 9.8.0 < 9.8.2.20, >= 9.9.0 < 9.9.1.2, 6.0.0, 6.0.1, 6.1.0, 6.2.0, 6.2.1, 6.2.2. Treat incomplete inventory results as unresolved.
Prioritize with independent signals
FIRST EPSS indicates an elevated probability of exploitation. Combine this signal with asset criticality, exposure, compensating controls, and business impact.
Apply supported remediation
Follow the vendor advisory or supported update path. Current fixed-version status: 9.1.7.23, 9.2.4.27, 9.4.4.16, 9.6.4.3, 9.7.1.21, 9.8.2.20, 9.9.1.2. Preserve configuration and rollback material before change.
Verify the result
Confirm the resulting version, service health, authentication and access paths, monitoring coverage, and relevant security logs.
- Confirm the expected version and package state.
- Run a functional health check for critical service paths.
- Review authentication, error, application, and security monitoring logs.
- Reassess exposure if the supported fix cannot be applied.
Operational boundary
This page does not replace the vendor advisory, support contract, change-management process, or recovery plan. Do not infer that an asset is unaffected from an incomplete inventory query or a missing fixed-version field.