CVE-2023-20109 remediation guide
Cisco IOS and IOS XE
A vulnerability in the Cisco Group Encrypted Transport VPN (GET VPN) feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker who has administrative control of either a group member or a key server to execute arbitrary code on an affected device or cause the device to crash. This vulnerability is due to insufficient validation of attributes in the Group Domain of Interpretation (GDOI) and G-IKEv2 protocols of the GET VPN feature. An attacker could exploit this vulnerability by either compromising an installed key server or modifying the configura...
A verified fixed-version field is not available. Use the linked NVD and supporting references, then confirm the vendor-supported path before changing production systems.
Identify the affected asset
Confirm whether Cisco IOS and IOS XE 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: 12.4(24)T, 12.4(24)T3, 12.4(22)T1, 12.4(24)T5, 12.4(24)T4, 12.4(22)T, 12.4(24)T8, 12.4(24)T2, 12.4(22)T5, 12.4(22)T4, 12.4(24)T1, 12.4(24)T7, 12.4(22)T3, 12.4(24)T6, 12.4(22)T2, 12.4(24)T4a, 12.4(24)T4b, 12.4(24)T3e, 12.4(24)T4c, 12.4(24)T4d. 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.