High severity8.6NVD Advisory· Published Jan 11, 2022· Updated Aug 11, 2026

CVE-2021-1573

Description

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to improper input validation when parsing HTTPS requests. An attacker could exploit this vulnerability by sending a malicious HTTPS request to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected products

Cisco Systems, Inc./Cisco Adaptive Security Appliance2 versions
cpe:2.3:a:cisco:adaptive_security_appliance:*:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:a:cisco:adaptive_security_appliance:*:*:*:*:*:*:*:*range: <=9.7
- cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*range: >=9.8,<9.8.4.40
Cisco Systems, Inc./Secure Firewall Threat Defense2 versions
cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*+ 1 more
- cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*range: <=6.2.2
- cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0:*:*:*:*:*:*:*
Cisco Systems, Inc./Adaptive Security Appliance (ASA) Softwarellm-fuzzy
Cisco Systems, Inc./Firepower Threat Defense Softwarellm-fuzzy2 versions
(expand)+ 1 more
- (no CPE)
- (no CPE)range: unspecified
Cisco Systems, Inc./Adaptive Security Appliance Cx Context Aware Security Softwarecpe-rescue
Range: unspecified

Patches

Vulnerability mechanics

References

tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asafdt-webvpn-dos-KSqJAKPAnvdVendor Advisory

News mentions

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