CVE-2021-34793 evidence review
Cisco Cisco Adaptive Security Appliance (ASA) Software, adaptive security appliance, secure firewall threat defense
A vulnerability in the TCP Normalizer of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software operating in transparent mode could allow an unauthenticated, remote attacker to poison MAC address tables, resulting in a denial of service (DoS) vulnerability. This vulnerability is due to incorrect handling of certain TCP segments when the affected device is operating in transparent mode. An attacker could exploit this vulnerability by sending a crafted TCP segment through an affected device. A successful exploit could allow the attacker to poison the MAC...
This record remains available for product and version identification, but it is not presented as a complete remediation procedure. Confirm the affected range and the supported fix in a direct vendor advisory before changing production systems.
Identify the product and installed version
Record whether Cisco Cisco Adaptive Security Appliance (ASA) Software, adaptive security appliance, secure firewall threat defense is present, where it is installed, and which interfaces are exposed.
- 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.
Compare the affected range
Use the current record as an identification aid: < 9.8.4.40, < 6.4.0.13, >= 6.5.0 < 6.6.5, >= 6.7.0 < 6.7.0.3, >= 9.9.0 < 9.12.4.29, >= 9.13.0 < 9.14.3.9, >= 9.15.0 < 9.15.1.17, >= 9.16.0 < 9.16.2.3, 009.008(004.025). Resolve incomplete inventory results before deciding that an asset is unaffected.
Verify the authoritative remediation source
Open the linked source material and locate a direct vendor advisory for this CVE. Confirm the supported fixed release and product-specific update path before making a production change.
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.