How severe is CVE-2021-43105?

CVE-2021-43105 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-43105 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43105?

CVE-2021-43105 affects Technitium Dns Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43105?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-43105 published?

CVE-2021-43105 was published on 2022-03-28 and last updated on 2026-06-17.

CVE-2021-43105

CVE-2021-43105 is a medium-severity vulnerability in Technitium Dns Server with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 4.0
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Technitium Dns Server
Published: 2022-03-28
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-43105?: 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.
How severe is CVE-2021-43105?: CVE-2021-43105 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-43105 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43105?: CVE-2021-43105 affects Technitium Dns Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43105?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-43105 published?: CVE-2021-43105 was published on 2022-03-28 and last updated on 2026-06-17.

References

https://github.com/TechnitiumSoftware/DnsServer/blob/master/CHANGELOG.md

Affected products (1)

cpe:2.3:a:technitium:dns_server:*:*:*:*:*:*:*:*

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