Cisco ASA Reachable Assertion (CVE-2021-1422)

high Tenable OT Security Plugin ID 506179

Synopsis

The remote OT asset is affected by a vulnerability.

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.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

Refer to the vendor advisory.

Plugin Details

Severity: High

ID: 506179

File Name: tenable_ot_cisco_CVE-2021-1422.nasl

Version: 1.1

Type: Remote

Family: Tenable.ot

Published: 10/6/2026

Updated: 10/6/2026

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3.3

Percentile: 50.71

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:C

CVSS Score Source: CVE-2021-1422

CVSS v3

Risk Factor: High

Base Score: 7.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Vulnerability Information

CPE: cpe:/o:cisco:adaptive_security_appliance_software:9.16.1

Required KB Items: Tenable.ot/Cisco

Patch Publication Date: 7/16/2021

Vulnerability Publication Date: 7/16/2021

Reference Information

CVE: CVE-2021-1422

CWE: 617

Detections

Analytics