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 address tables in adjacent devices, resulting in network disruption.
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Cisco Asa | — | Upgrade to the latest version of Cisco ASA to resolve this vulnerability. | Nov 26, 2021 | Oct 27, 2021 |
| Cisco Ftd | — | Upgrade to the latest version of Cisco FTD to resolve this vulnerability. | Jan 29, 2025 | Oct 27, 2021 |
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