Cisco Adaptive Security Appliance Software Release 9.16.1 and Cisco Firepower Threat Defense Software Release 7.0.0 IPsec Denial of Service Vulnerability

Summary

CVECVE-2021-1422
StatePUBLISHED
Assignercisco
Source PriorityCVE Program / NVD first with legacy fallback
Published2021-07-16 13:15:08 UTC
Updated2026-08-11 19:42:47 UTC
DescriptionA vulnerability in the software cryptography module of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker or an unauthenticated attacker in a man-in-the-middle position to cause an unexpected reload of the device that results in a denial of service (DoS) condition. The vulnerability is due to a logic error in how the software cryptography module handles specific types of decryption errors. An attacker could exploit this vulnerability by sending malicious packets over an established IPsec connection. A successful exploit could cause the device to crash, forcing it to reload. Important: Successful exploitation of this vulnerability would not cause a compromise of any encrypted data. Note: This vulnerability affects only Cisco ASA Software Release 9.16.1 and Cisco FTD Software Release 7.0.0.

Risk And Classification

Primary CVSS: v3.1 7.7 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

EPSS: 0.011880000 probability, percentile 0.650680000 (date 2026-08-12)

Problem Types: CWE-617 | CWE-617 CWE-617


VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary7.7HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
3.1[email protected]Secondary7.7HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
3.1CNADECLARED7.7HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
2.0[email protected]Primary6.8AV:N/AC:L/Au:S/C:N/I:N/A:C

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

CVSS v2.0 Breakdown

Access Vector
Network
Access Complexity
Low
Authentication
Single
Confidentiality
None
Integrity
None
Availability
Complete

AV:N/AC:L/Au:S/C:N/I:N/A:C

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Cisco Adaptive Security Appliance Software 9.16.1 All All All
Application Cisco Adaptive Security Virtual Appliance - All All All
Hardware Cisco Firepower 2100 - All All All
Hardware Cisco Firepower 2110 - All All All
Hardware Cisco Firepower 2120 - All All All
Hardware Cisco Firepower 2130 - All All All
Hardware Cisco Firepower 2140 - All All All
Hardware Cisco Ftd Virtual - All All All
Application Cisco Secure Firewall Threat Defense 7.0.0.0 All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Cisco Cisco Adaptive Security Appliance ASA Software affected n/a Not specified

References

ReferenceSourceLinkTags
Cisco Adaptive Security Appliance Software Release 9.16.1 and Cisco Firepower Threat Defense Software Release 7.0.0 IPsec Denial of Service Vulnerability af854a3a-2127-422b-91ae-364da2661108 tools.cisco.com Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

Exploits

CNA: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Legacy QID Mappings

  • 316998 Cisco Adaptive Security Appliance Software Release 9.16.1 IPsec Denial of Service Vulnerability(cisco-sa-asa-ftd-ipsec-dos-TFKQbgWC)
  • 316999 Cisco Firepower Threat Defense Software Release 7.0.0 IPsec Denial of Service Vulnerability(cisco-sa-asa-ftd-ipsec-dos-TFKQbgWC)

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