How severe is CVE-2021-36754?

CVE-2021-36754 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-36754 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 65% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-36754?

CVE-2021-36754 affects Powerdns Authoritative Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-36754?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-36754 published?

CVE-2021-36754 was published on 2021-07-30 and last updated on 2026-06-17.

CVE-2021-36754

CVE-2021-36754 is a high-severity vulnerability in Powerdns Authoritative Server with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 65% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-119.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 65% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Powerdns Authoritative Server
Published: 2021-07-30
Last modified: 2026-06-17

Description

PowerDNS Authoritative Server 4.5.0 before 4.5.1 allows anybody to crash the process by sending a specific query (QTYPE 65535) that causes an out-of-bounds exception.

Frequently asked questions

What is CVE-2021-36754?: PowerDNS Authoritative Server 4.5.0 before 4.5.1 allows anybody to crash the process by sending a specific query (QTYPE 65535) that causes an out-of-bounds exception.
How severe is CVE-2021-36754?: CVE-2021-36754 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-36754 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 65% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-36754?: CVE-2021-36754 affects Powerdns Authoritative Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-36754?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-36754 published?: CVE-2021-36754 was published on 2021-07-30 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:powerdns:authoritative_server:*:*:*:*:*:*:*:*

More vulnerabilities in Powerdns Authoritative Server

CVE-2022-27227 — High (CVSS 7.5): In PowerDNS Authoritative Server before 4.4.3, 4.5.x before 4.5.4, and 4.6.x before 4.6.1 and PowerDNS Recursor before…
CVE-2016-6172 — Medium (CVSS 6.8): PowerDNS (aka pdns) Authoritative Server before 4.0.1 allows remote primary DNS servers to cause a denial of service…
CVE-2019-3871 — Medium (CVSS 6.5): A vulnerability was found in PowerDNS Authoritative Server before 4.0.7 and before 4.1.7. An insufficient validation of…
CVE-2008-3337 — Medium (CVSS 6.4): PowerDNS Authoritative Server before 2.9.21.1 drops malformed queries, which might make it easier for remote attackers…
CVE-2012-0206 — Medium (CVSS 5.0): common_startup.cc in PowerDNS (aka pdns) Authoritative Server before 2.9.22.5 and 3.x before 3.0.1 allows remote…
CVE-2019-10203 — Medium (CVSS 4.3): PowerDNS Authoritative daemon , pdns versions 4.0.x before 4.0.9, 4.1.x before 4.1.11, exiting when encountering a…

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