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Fencer Vulns
high 7.5

CVE-2020-10995 json

PowerDNS Recursor from 4.1.0 up to and including 4.3.0 does not sufficiently defend against amplification attacks.

published 2020-05-19 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-3392

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.5%
EPSS 4.5% chance of exploitation in 30 days, percentile 91%
public exploits
0
none known

Summary

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.

Patch / fix

  • pdns-recursor Debian 14, Debian 13, Debian 12 4.3.1-1

debian advisories DEBIAN-CVE-2020-10995

  • pdns-recursor openSUSE Tumbleweed 4.5.5-1.3
  • pdns-recursor Package Hub 15 SP1, Package Hub 12 SP1, openSUSE Leap 15.1 4.1.12-bp151.4.3.1

opensuse advisories openSUSE-SU-2024:11157-1openSUSE-SU-2020:0698-1

  • pdns-recursor Alpine 3.10, Alpine 3.9 4.1.16-r0
  • pdns-recursor Alpine 3.11 4.2.2-r0
  • pdns-recursor Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 4.3.1-r0

alpine advisories ALPINE-CVE-2020-10995

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • powerdns-recursor Arch Linux 4.2.2-1

arch linux advisories AVG-1163

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-10995 updated cvss 7.5

pdns-recursor: issue in DNS protocol allows malicious parties to use recursive DNS services to attack third party authoritative name servers

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

4.48% chance of exploitation in the next 30 days, higher than 91% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.