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Fencer Intel
high 7.5

CVE-2022-3204 json

NRDelegation Attack

published 4y ago modified 4mo ago also EUVD-2022-42621

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

A vulnerability named 'Non-Responsive Delegation Attack' (NRDelegation Attack) has been discovered in various DNS resolving software. The NRDelegation Attack works by having a malicious delegation with a considerable number of non responsive nameservers. The attack starts by querying a resolver for a record that relies on those unresponsive nameservers. The attack can cause a resolver to spend a lot of time/resources resolving records under a malicious delegation point where a considerable number of unresponsive NS records reside. It can trigger high CPU usage in some resolver implementations that continually look in the cache for resolved NS records in that delegation. This can lead to degraded performance and eventually denial of service in orchestrated attacks. Unbound does not suffer from high CPU usage, but resources are still needed for resolving the malicious delegation. Unbound will keep trying to resolve the record until hard limits are reached. Based on the nature of the attack and the replies, different limits could be reached. From version 1.16.3 on, Unbound introduces fixes for better performance when under load, by cutting opportunistic queries for nameserver discovery and DNSKEY prefetching and limiting the number of times a delegation point can issue a cache lookup for missing records.

Patch / fix

  • unbound Debian 14, Debian 13, Debian 12 1.16.3-1

debian advisories DEBIAN-CVE-2022-3204

  • unbound Ubuntu 18.04 LTS 1.6.7-1ubuntu2.6
  • unbound Ubuntu 20.04 LTS 1.9.4-2ubuntu1.4
  • unbound Ubuntu 22.04 LTS 1.13.1-1ubuntu5.3

ubuntu advisories UBUNTU-CVE-2022-3204

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • unbound RHEL 8 1.16.2-5.el8
  • unbound-libs RHEL 8 1.16.2-5.el8
  • python3-unbound RHEL 8 1.16.2-5.el8
  • unbound RHEL 9 1.16.2-3.el9
  • unbound-libs RHEL 9 1.16.2-3.el9
  • python3-unbound RHEL 9 1.16.2-3.el9
  • unbound RHEL 8.6 EUS 1.7.3-17.el8_6.5
  • unbound-libs RHEL 8.6 EUS 1.7.3-17.el8_6.5

red hat advisories RHSA-2024:2045RHSA-2023:2771RHSA-2023:2370

  • unbound SLE Module for Package Hub 15 SP5, SLE Module for Basesystem 15 SP5, SLE Micro 5.5 +14 more 1.20.0-150100.10.13.1
  • unbound SLE Module for Package Hub 15 SP6, SLE Module for Basesystem 15 SP6, openSUSE Leap 15.6 1.20.0-150600.23.3.1

suse advisories SUSE-SU-2024:1991-2SUSE-SU-2024:1991-1SUSE-SU-2024:1923-1

  • unbound openSUSE Tumbleweed 1.16.3-1.1

opensuse advisories openSUSE-SU-2024:12368-1

  • unbound AlmaLinux 8 1.16.2-5.el8
  • unbound-libs AlmaLinux 8 1.16.2-5.el8
  • python3-unbound AlmaLinux 8 1.16.2-5.el8
  • unbound AlmaLinux 9 1.16.2-3.el9
  • unbound-libs AlmaLinux 9 1.16.2-3.el9
  • python3-unbound AlmaLinux 9 1.16.2-3.el9

almalinux advisories ALSA-2023:2771ALSA-2023:2370

  • unbound Rocky Linux 8 1.16.2-5.12.el8_10

rocky linux advisories RLSA-2023:2771

  • unbound Alpine 3.24, Alpine 3.23, Alpine 3.22 +5 more 1.16.3-r0

alpine advisories ALPINE-CVE-2022-3204

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

  • unbound CBL-Mariner 2.0 1.16.3-1

azure linux advisories AZL-11033

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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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-2022-3204 updated cvss 7.5

unbound: NRDelegation attack leads to uncontrolled resource consumption (Non-Responsive Delegation Attack)

  • Red Hat Enterprise Linux 6 unbound, unbound-libs, unbound-python Red Hat Enterprise Linux 7 unbound, unbound-libs, unbound-python Red Hat JBoss Data Grid 7 unbound Red Hat Process Automation 7 unbound
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux AppStream (v. 8) unbound 1.16.2-5.el8, unbound-libs 1.16.2-5.el8, python3-unbound 1.16.2-5.el8
    fixed: vendor fix RHSA-2023:2771
  • Red Hat Enterprise Linux AppStream (v. 9) unbound 1.16.2-3.el9, unbound-libs 1.16.2-3.el9, python3-unbound 1.16.2-3.el9
    fixed: vendor fix RHSA-2023:2370
  • Red Hat Enterprise Linux AppStream EUS (v.8.6) unbound 1.7.3-17.el8_6.5, unbound-libs 1.7.3-17.el8_6.5, python3-unbound 1.7.3-17.el8_6.5
    fixed: vendor fix RHSA-2024:2045
  • Red Hat Enterprise Linux CRB (v. 9) unbound-devel 1.16.2-3.el9, unbound-debuginfo 1.16.2-3.el9, unbound-debugsource 1.16.2-3.el9, unbound-libs-debuginfo 1.16.2-3.el9, python3-unbound-debuginfo 1.16.2-3.el9
    fixed: vendor fix RHSA-2023:2370
  • Red Hat Data Grid 8 unbound Red Hat JBoss Enterprise Application Platform 7 unbound Red Hat JBoss Enterprise Application Platform Expansion Pack unbound
    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

cisa ICSA-23-234-01 updated cvss 7.5

Hitachi Energy AFF66x

  • Hitachi Energy AFF660/665 <= 03.0.02
    affected: vendor fix, mitigation “Hitachi Energy recommends the following actions:” search.abb.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
last yr.

Exploit prediction

1.65% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • NLnet Labs Unbound

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Intel 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.