CVE-2020-10995

Name: CVE-2020-10995
Creator: NVD / NIST
Published: 2020-05-19T17:15:10.163+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 4.37%

Last modified Jun 17, 2026

CVE-2020-10995 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. PowerDNS Recursor from 4.1.0 up to and including 4.3.0 does not sufficiently defend against amplification attacks. An issue in the DNS protocol has been found that allow malicious parties to use recursive DNS services to attack third party authoritative name servers. EPSS estimates a 4.37% chance of exploitation in the next 30 days.

Description

PowerDNS Recursor from 4.1.0 up to and including 4.3.0 does not sufficiently defend against amplification attacks. An issue in the DNS protocol has been found that allow malicious parties to use recursive DNS services to attack third party authoritative name servers. The attack uses a crafted reply by an authoritative name server to amplify the resulting traffic between the recursive and other authoritative name servers. Both types of service can suffer degraded performance as an effect. This is triggered by random subdomains in the NSDNAME in NS records. PowerDNS Recursor 4.1.16, 4.2.2 and 4.3.1 contain a mitigation to limit the impact of this DNS protocol issue.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

4.37%

90.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-400

Affected Software

Vendor	Product	Versions	Update
Powerdns	Recursor	>= 4.1.0, <= 4.3.0	—
Fedoraproject	Fedora	31	—
Fedoraproject	Fedora	32	—
Debian	Debian Linux	10.0	—
Opensuse	Backports Sle	15.0	Sp1
Opensuse	Leap	15.1	—

References

http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00052.htmlMailing List, Third Party Advisory
http://www.nxnsattack.comTechnical Description, Third Party Advisory
https://doc.powerdns.com/recursor/security-advisories/powerdns-advisory-2020-01.htmlVendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NMP72NJGKBWR5WEBXAWX5KSLQUDFTG6S/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PS4ZN5XGENYNFKX7QIIOUCQQHXE37GJF/
https://www.debian.org/security/2020/dsa-4691Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00052.htmlMailing List, Third Party Advisory
http://www.nxnsattack.comTechnical Description, Third Party Advisory
https://doc.powerdns.com/recursor/security-advisories/powerdns-advisory-2020-01.htmlVendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NMP72NJGKBWR5WEBXAWX5KSLQUDFTG6S/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PS4ZN5XGENYNFKX7QIIOUCQQHXE37GJF/
https://www.debian.org/security/2020/dsa-4691Third Party Advisory

Timeline

Published: May 19, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-10995?

How severe is CVE-2020-10995?

CVE-2020-10995 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 4.37% probability of exploitation in the next 30 days.

How do I fix CVE-2020-10995?

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-2020-10995?

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

Scan your code now

Source: NVD / NIST