CVE-2020-3259 remediation guide
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)
A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to retrieve memory contents on an affected device, which could lead to the disclosure of confidential information. The vulnerability is due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. An attacker could exploit this vulnerability by sending a crafted GET request to the web services interface. A successful exploit could allow th...
Identify the affected asset
Confirm whether Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) 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: 6.2.3, 6.3.0, 6.4.0, 6.5.0, 9.8, 9.9, 9.10, 9.12, 9.13, >= 6.2.3 < 6.2.3.16, >= 6.3.0 < 6.3.0.6, >= 6.4.0 < 6.4.0.9, >= 6.5.0 < 6.5.0.5, >= 9.8 < 9.8.4.20, >= 9.9 < 9.9.2.67, >= 9.10 < 9.10.1.40, >= 9.12 < 9.12.3.9, >= 9.13 < 9.13.1.10. Treat incomplete inventory results as unresolved.
Prioritize with independent signals
CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog. Combine this signal with asset criticality, exposure, compensating controls, and business impact.
Apply supported remediation
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
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.