CVE-2021-43105

Name: CVE-2021-43105
Creator: NVD / NIST
Published: 2022-03-28T23:15:07.717+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.60%

Last modified Jun 17, 2026

CVE-2021-43105 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. A vulnerability in the bailiwick checking function in Technitium DNS Server <= v7.0 exists that allows specific malicious users to inject `NS` records of any domain (even TLDs) into the cache and conduct a DNS cache poisoning attack.. EPSS estimates a 0.60% chance of exploitation in the next 30 days.

Description

A vulnerability in the bailiwick checking function in Technitium DNS Server <= v7.0 exists that allows specific malicious users to inject `NS` records of any domain (even TLDs) into the cache and conduct a DNS cache poisoning attack.

Metrics

CVSS 3.1

4.3/10

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

EPSS Probability

0.60%

44.2th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Technitium	Dns Server	<= 7.0

References

https://github.com/TechnitiumSoftware/DnsServer/blob/master/CHANGELOG.mdRelease Notes, Third Party Advisory
https://github.com/TechnitiumSoftware/DnsServer/blob/master/CHANGELOG.mdRelease Notes, Third Party Advisory

Timeline

Published: Mar 28, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-43105?

How severe is CVE-2021-43105?

CVE-2021-43105 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.60% probability of exploitation in the next 30 days.

How do I fix CVE-2021-43105?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-43105?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST