CVE-2021-34792: Cisco Adaptive Security Appliance Software

High severity, CVSS 7.5. EPSS: 1.4% chance of exploitation in the next 30 days.

A vulnerability in the memory management of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper resource management when connection rates are high. An attacker could exploit this vulnerability by opening a significant number of connections on an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Affected products

Cisco Adaptive Security Appliance Software: from 9.8.0, before 9.8.4.40 (fixed in 9.8.4.40); from 9.12.0, before 9.12.4.29 (fixed in 9.12.4.29); from 9.14.0, before 9.14.3.9 (fixed in 9.14.3.9); from 9.15.0, before 9.15.1.17 (fixed in 9.15.1.17); from 9.16.0, before 9.16.2.3 (fixed in 9.16.2.3)
Cisco ASA 5505 Firmware: version 009.014(001.150) only; version 099.017(001.211) only; version 099.017(001.220) only; version 099.017(015.050) only
Cisco ASA 5512-X Firmware: version 009.014(001.150) only; version 099.017(001.211) only; version 099.017(001.220) only; version 099.017(015.050) only
Cisco ASA 5515-X Firmware: version 009.014(001.150) only; version 099.017(001.211) only; version 099.017(001.220) only; version 099.017(015.050) only
Cisco ASA 5525-X Firmware: version 009.014(001.150) only; version 099.017(001.211) only; version 099.017(001.220) only; version 099.017(015.050) only
Cisco ASA 5545-X Firmware: version 009.014(001.150) only; version 099.017(001.211) only; version 099.017(001.220) only; version 099.017(015.050) only
Cisco ASA 5555-X Firmware: version 009.014(001.150) only; version 099.017(001.211) only; version 099.017(001.220) only; version 099.017(015.050) only
Cisco ASA 5580 Firmware: version 009.014(001.150) only; version 099.017(001.211) only; version 099.017(001.220) only; version 099.017(015.050) only
Cisco ASA 5585-X Firmware: version 009.014(001.150) only; version 099.017(001.211) only; version 099.017(001.220) only; version 099.017(015.050) only
Cisco Secure Firewall Threat Defense: from 6.4.0, before 6.4.0.13 (fixed in 6.4.0.13); from 6.6.0, before 6.6.5 (fixed in 6.6.5); from 6.7.0, before 6.7.0.3 (fixed in 6.7.0.3); from 7.0.0, before 7.0.1 (fixed in 7.0.1)

Published 2021-10-27. Last modified 2026-08-11.