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Fencer Vulns
high 7.5

CVE-2020-25829 json

An issue has been found in PowerDNS Recursor before 4.1.18, 4.2.x before 4.2.5, and 4.3.x before 4.3.5.

published 2020-10-16 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-18463

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
6.5%
EPSS 6.5% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

An issue has been found in PowerDNS Recursor before 4.1.18, 4.2.x before 4.2.5, and 4.3.x before 4.3.5. A remote attacker can cause the cached records for a given name to be updated to the Bogus DNSSEC validation state, instead of their actual DNSSEC Secure state, via a DNS ANY query. This results in a denial of service for installation that always validate (dnssec=validate), and for clients requesting validation when on-demand validation is enabled (dnssec=process).

Patch / fix

  • powerdns recursor 4.1.18, 4.2.5, 4.3.5
  • pdns-recursor Debian 14, Debian 13, Debian 12 4.3.5-1

debian advisories DEBIAN-CVE-2020-25829

  • pdns-recursor openSUSE Tumbleweed 4.5.5-1.3
  • pdns-recursor Package Hub 15 SP2, Package Hub 15 SP1, Package Hub 12 SP1 +2 more 4.3.5-bp152.2.12.1

opensuse advisories openSUSE-SU-2024:11157-1openSUSE-SU-2020:1687-1

  • pdns-recursor Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 4.3.5-r0

alpine advisories ALPINE-CVE-2020-25829

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 4.3.5-1

arch linux advisories AVG-1243

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-2020-25829 updated cvss 5.9

pdns-recursor: remote attacker can cause the cached records for a given name to be updated to the ‘Bogus’ DNSSEC validation state instead of their actual DNSSEC ‘Secure’ state via a DNS ANY query

  • 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

6.54% chance of exploitation in the next 30 days, higher than 93% 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

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.