CVE-2021-1619

9.8 CRITICAL 2% exploit odds Fix listed Memory safety Network gear

What it is

A vulnerability in the authentication, authorization, and accounting (AAA) function of Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass NETCONF or RESTCONF authentication and do either of the following: Install, manipulate, or delete the configuration of an affected device Cause memory corruption that results in a denial of service (DoS) on an affected device This vulnerability is due to an uninitialized variable. An attacker could exploit this vulnerability by sending a series of NETCONF or RESTCONF requests to an affected device. A successful exploit could allow the attacker to use NETCONF or RESTCONF to install, manipulate, or delete the configuration of a network device or to corrupt memory on the device, resulting a DoS.

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
Exploit odds: 1.8% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2021-09-23 03:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 03:32 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 1.8% in the next 30 days (EPSS).
Severity: 9.8 CRITICAL (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2021-09-23 03:15 UTC
Last modified: 2026-06-17 03:32 UTC
Exploit probability: 1.8% · EPSS, next 30 days
Weakness: CWE-824
Record status: Undergoing Analysis

Affected

Cisco iOS Xe 16.3.1
Cisco iOS Xe 16.3.1a
Cisco iOS Xe 16.3.2
Cisco iOS Xe 16.3.3
Cisco iOS Xe 16.3.4
Cisco iOS Xe 16.3.5
Cisco iOS Xe 16.3.5b
Cisco iOS Xe 16.3.6

Attack profile CVSS 3.1 · 9.8

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-1619.md and follow it. Check whether this project is affected by CVE-2021-1619. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record