No exploitation reported

CVE-2021-1422

No exploitation reported by the sources we read.

Published2021-07-16
WeaknessCWE-617

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

A 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.

Timeline

dates in UTC

2021-07-1613:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-1422?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-1422?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Cisco ASAversion to verify

Branch	Affected	Fixed in	Source
9.16	= 9.16.1	no fix published	NVD

Cisco secure firewall threat defenseversion to verify

Branch	Affected	Fixed in	Source
7.0	= 7.0.0.0	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

tools.cisco.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CISA-ADPSSVC decisionnone2024-11-07
OpenCVESSVC decisionnone—
CNACVSS 3.17.7read 2026-10-23
NVDCVSS 3.17.7read 2026-10-23
NVDCVSS 2.06.8read 2026-10-23
CNAweakness (CWE)CWE-617read 2026-10-23
NVDweakness (CWE)CWE-617read 2026-10-23
FIRST EPSSEPSS score1.2 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Published: 2021-07-16
Last Modified: 2026-08-11
NVD status: Modified

Frequently asked questions

What is CVE-2021-1422?

Is CVE-2021-1422 actively exploited?

Active exploitation of CVE-2021-1422 has not been confirmed. Its EPSS score was 1.2% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-1422?

CVE-2021-1422 has a CVSS v3 base score of 7.7 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.

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