CVE-2016-6171

Knot DNS before 2.3.0 allows remote DNS servers to cause a denial of service (memory exhaustion...

8.6 HighFix available

Knot DNS before 2.3.0 allows remote DNS servers to cause a denial of service (memory exhaustion and slave server crash) via a large zone transfer for (1) DDNS, (2) AXFR, or (3) IXFR.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

2.80%Up 1.7 points since Feb 4, 2022

What each source reports

NVD Score used 8.6

Knot DNS before 2.3.0 allows remote DNS servers to cause a denial of service (memory exhaustion and slave server crash) via a large zone transfer for (1) DDNS, (2) AXFR, or (3) IXFR.

Record: CVE-2016-6171
CVSS 3.1: 8.6 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Weakness: CWE-400
Updated: 2026-11-02

CVE List No score

Knot DNS before 2.3.0 allows remote DNS servers to cause a denial of service (memory exhaustion and slave server crash) via a large zone transfer for (1) DDNS, (2) AXFR, or (3) IXFR.

Record: CVE-2016-6171
Updated: 2026-11-02

EUVDEUVD-2016-7105 No score

Knot DNS before 2.3.0 allows remote DNS servers to cause a denial of service (memory exhaustion and slave server crash) via a large zone transfer for (1) DDNS, (2) AXFR, or (3) IXFR.

Record: EUVD-2016-7105
Updated: 2026-11-03

GitHub AdvisoriesGHSA-935v-fg4c-f9fr 8.6

Knot DNS before 2.3.0 allows remote DNS servers to cause a denial of service (memory exhaustion...

Knot DNS before 2.3.0 allows remote DNS servers to cause a denial of service (memory exhaustion and slave server crash) via a large zone transfer for (1) DDNS, (2) AXFR, or (3) IXFR.

Record: GHSA-935v-fg4c-f9fr
CVSS 3.1: 8.6 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Weakness: CWE-400
Updated: 2026-11-02

OSV 8.6

Knot DNS before 2.3.0 allows remote DNS servers to cause a denial of service (memory exhaustion and slave server crash) via a large zone transfer for (1) DDNS, (2) AXFR, or (3) IXFR.

Record: CVE-2016-6171
CVSS 3.1: 8.6 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2016-6171 8.6

Knot DNS before 2.3.0 allows remote DNS servers to cause a denial of service (memory exhaustion and slave server crash) via a large zone transfer for (1) DDNS, (2) AXFR, or (3) IXFR.

Record: DEBIAN-CVE-2016-6171
CVSS 3.1: 8.6 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2016-6171 8.6

Knot DNS before 2.3.0 allows remote DNS servers to cause a denial of service (memory exhaustion and slave server crash) via a large zone transfer for (1) DDNS, (2) AXFR, or (3) IXFR.

Record: UBUNTU-CVE-2016-6171
CVSS 3.1: 8.6 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Updated: 2026-11-02

Affected products

knot-dns knot dns

Affected packages

Affected packages
Package	Affected	Fixed
`knot` Debian:12	before 2.3.0-1	2.3.0-1
`knot` Debian:13	before 2.3.0-1	2.3.0-1
`knot` Debian:14	before 2.3.0-1	2.3.0-1
`knot` Ubuntu:16.04:LTS	All versions, plus listed versions 2.0.0-12.0.1-42.0.1-4build12.0.2-12.0.2-1build1 Show 6 moreShow less 2.1.0~rc1-52-gd80ce77-12.1.0~rc1-55-gf227348-12.1.0-22.1.0-32.1.1-12.1.1-1build1	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2016-6171 is a high vulnerability (CVSS 8.6) in Knot-dns Knot Dns, published February 9, 2017. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.80%, the 86th percentile. Fixed in knot 2.3.0-1.

References

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