CVE-2021-34793
Description
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.
How to fix
- cisco adaptive_security_appliance9.8.4.40 or later
- cisco secure_firewall_threat_defense6.4.0.13, 6.6.5, 6.7.0.3 or later
- cisco adaptive_security_appliance_software9.12.4.29, 9.14.3.9, 9.15.1.17, 9.16.2.3 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| cisco adaptive_security_appliance | v < 9.8.4.40 | 9.8.4.40 |
| cisco secure_firewall_threat_defense | v < 6.4.0.13, 6.5.0 ≤ v < 6.6.5, 6.7.0 ≤ v < 6.7.0.3 | 6.4.0.13, 6.6.5, 6.7.0.3 |
| cisco adaptive_security_appliance_software | 9.9.0 ≤ v < 9.12.4.29, 9.13.0 ≤ v < 9.14.3.9, 9.15.0 ≤ v < 9.15.1.17, 9.16.0 ≤ v < 9.16.2.3 | 9.12.4.29, 9.14.3.9, 9.15.1.17, 9.16.2.3 |
| cisco asa_5512-x_firmware | 009.008\(004.025\) | — |
| cisco asa_5505_firmware | 009.008\(004.025\) | — |
| cisco asa_5515-x_firmware | 009.008\(004.025\) | — |
| cisco asa_5525-x_firmware | 009.008\(004.025\) | — |
| cisco asa_5545-x_firmware | 009.008\(004.025\) | — |
| cisco asa_5555-x_firmware | 009.008\(004.025\) | — |
| cisco asa_5580_firmware | 009.008\(004.025\) | — |
| cisco asa_5585-x_firmware | 009.008\(004.025\) | — |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.