CVE-2021-34783

highpriority · track · 31EPSS 0.016 · 76 %ileEURUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

1.61% (76th) EPSS

CVSS 7.8 · high

Is it mine?

188 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in the software-based SSL/TLS message handler of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient validation of SSL/TLS messages when the device performs software-based SSL/TLS decryption. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: Datagram TLS (DTLS) messages cannot be used to exploit this vulnerability.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1 when installed on Cisco Adaptive Security Virtual Appliance (ASAv)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1.28 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1.28 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1.28 when installed on Cisco Adaptive Security Virtual Appliance (ASAv)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1.28 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1.28 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1.28 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1.28 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.1 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.1 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.1 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.1 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.1 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.1 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.10 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.10 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.10 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.10 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.10 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.10 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.10 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.11 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.11 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.11 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.11 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.11 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.11 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.11 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.12 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.12 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.12 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.12 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.12 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.12 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.12 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.2 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.2 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.2 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.2 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.2 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.2 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.2 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.3 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.3 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.3 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.3 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.3 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.3 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.3 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.4 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.4 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.4 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.4 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.4 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.4 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.4 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.5 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.5 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.5 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.5 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.5 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.5 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.5 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.6 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.6 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.6 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.6 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.6 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.6 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.6 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.7 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.7 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.7 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.7 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.7 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.7 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.7 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.8 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.8 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.8 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.8 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.8 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.8 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.8 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.9 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.9 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.9 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.9 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.9 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.9 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.4.0.9 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0.1 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0.1 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0.1 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0.1 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0.1 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0.1 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.0.1 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.1 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.1 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.1 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.1 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.1 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.1 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.1 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.3 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.3 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.3 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.3 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.3 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.3 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.3 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.4 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.4 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.4 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.4 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.4 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.4 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 6.6.4 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco 3000 Series Industrial Security Appliances (ISA)cisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco ASA 5500-X Series Firewallscisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 1000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 2100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 4100 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Firepower 9000 Seriescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco Secure Firewall Threat Defense (FTD) Software 7.0.0.1 when installed on Cisco Secure Firewall Threat Defense Virtualcisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

Technical severity, 0–10. One row per scoring source.

8.6

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–8.6

v2.07.8highAV:N/AC:L/Au:N/C:N/I:N/A:Cprimary · NVD / NIST USexploitability 10 · impact 6.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.18.6highAV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · ENISA EU

v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · psirt@cisco.com USexploitability 3.9 · impact 4

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

v3.18.6highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · Cisco PSIRT US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USprimaryCWE-119USCWE-119US

affected products (188)

Products and version ranges known to be affected.

showing 20 of 188

advisories (1)

Vendor and ecosystem advisories describing this.

cisco-sa-ftd-tls-decrypt-dos-BMxYjm8MCisco Adaptive Security Appliance Software and Firepower Threat Defense Software Software-Based SSL/TLS Denial of Service Vulnerability2021-10-27csaf · cisco_csafUS
A vulnerability in the software-based SSL/TLS message handler of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient validation of SSL/TLS messages when the device performs software-based SSL/TLS decryption. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: Datagram TLS (DTLS) messages cannot be used to exploit this vulnerability. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is part of the October 2021 release of the Cisco ASA, FTD, and FMC Security Advisory Bundled publication. For a complete list of the advisories and links to them, see Cisco Event Response: October 2021 Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-74773"].

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisco_csaf NVD CVE.org MITRE

published 2021-10-27modified 2026-08-11

related (25,176)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2026-88771US	critical9.8OT critical	82.2% (100th)	KEV	2026-09-27
Improper input validation vulnerability in Citrix NetScaler ADC and Citrix NetScaler Gateway. This issue affects ADC: before 14.1-73.37, before 13.1-64.23, before 14.1-73.37 FIPS,…
CVE-2026-93952US	—OT critical	1.38% (72nd)	KEV	2026-09-22
VeloCloud Orchestrator (VCO) on-prem has a security issue where this issue may allow a remote attacker to access privileged internal functionality and impact the VCO host. Successf…
CVE-2026-12569US	critical9.8OT critical	46.0% (99th)	KEV	2026-06-18
A critical remote code execution (RCE) vulnerability has been reported in PTC Windchill PDMlink and PTC FlexPLM. The vulnerability may be exploited through the deserialization of u…
CVE-2026-34910US	—OT critical	90.0% (100th)	KEV	2026-05-22
A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS devices to execute a Command Injection.
CVE-2026-6973US	—OT critical	34.5% (98th)	KEV	2026-05-07
An Improper Input Validation in Ivanti EPMM before versions 12.6.1.1, 12.7.0.1, and 12.8.0.1 allows a remotely authenticated user with administrative access to achieve remote code…

+25171 more

references (7)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan