# CVE-2022-3204: NRDelegation Attack > Attackers can cause denial of service in DNS resolvers by exploiting non-responsive delegation attacks, leading to resource exhaustion and degraded performance. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 26 Sep 2022 - **Updated:** 5 May 2025 - **Also known as:** ALPINE-CVE-2022-3204, ALSA-2023:2370, ALSA-2023:2771, AZL-11033, CLSA-2024-1725554505, DEBIAN-CVE-2022-3204, GHSA-7mc5-x7xh-682h, MGASA-2022-0361, OESA-2022-1972, RHSA-2023:2370, RHSA-2023:2771, RLSA-2023:2771, UBUNTU-CVE-2022-3204, USN-5732-1, openSUSE-SU-2024:12368-1 ## What is CVE-2022-3204? CVE-2022-3204 is a high-severity denial of service vulnerability in Fedoraproject Fedora, published on 26 Sep 2022. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description 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. Weakness: CWE-400 (Uncontrolled Resource Consumption) ## Which versions are affected by CVE-2022-3204? It affects 2 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `python3-unbound` | AlmaLinux:8 | All versions | 1.16.2-5.el8 | | `unbound` | AlmaLinux:8 | All versions | 1.16.2-5.el8 | | `unbound-devel` | AlmaLinux:8 | All versions | 1.16.2-5.el8 | | `unbound-libs` | AlmaLinux:8 | All versions | 1.16.2-5.el8 | | `python3-unbound` | AlmaLinux:9 | All versions | 1.16.2-3.el9 | | `unbound` | AlmaLinux:9 | All versions | 1.16.2-3.el9 | | `unbound-devel` | AlmaLinux:9 | All versions | 1.16.2-3.el9 | | `unbound-libs` | AlmaLinux:9 | All versions | 1.16.2-3.el9 | | `python3-unbound` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.16.2-5.el8 | | `python3-unbound-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.16.2-5.el8 | | `unbound` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.16.2-5.el8 | | `unbound-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.16.2-5.el8 | | `unbound-debugsource` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.16.2-5.el8 | | `unbound-devel` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.16.2-5.el8 | | `unbound-libs` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.16.2-5.el8 | | `unbound-libs-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.16.2-5.el8 | | `python3-unbound` | Red Hat:enterprise_linux:9::appstream | All versions | 0:1.16.2-3.el9 | | `python3-unbound-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:1.16.2-3.el9 | | `unbound` | Red Hat:enterprise_linux:9::appstream | All versions | 0:1.16.2-3.el9 | | `unbound-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:1.16.2-3.el9 | | `unbound-debugsource` | Red Hat:enterprise_linux:9::appstream | All versions | 0:1.16.2-3.el9 | | `unbound-libs` | Red Hat:enterprise_linux:9::appstream | All versions | 0:1.16.2-3.el9 | | `unbound-libs-debuginfo` | Red Hat:enterprise_linux:9::appstream | All versions | 0:1.16.2-3.el9 | | `python3-unbound-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 0:1.16.2-3.el9 | | `unbound-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 0:1.16.2-3.el9 | | `unbound-debugsource` | Red Hat:enterprise_linux:9::crb | All versions | 0:1.16.2-3.el9 | | `unbound-devel` | Red Hat:enterprise_linux:9::crb | All versions | 0:1.16.2-3.el9 | | `unbound-libs-debuginfo` | Red Hat:enterprise_linux:9::crb | All versions | 0:1.16.2-3.el9 | | `unbound` | Rocky Linux:8 | All versions | 0:1.16.2-5.12.el8_10 | | `unbound` | openSUSE:Tumbleweed | All versions | 1.16.3-1.1 | Products: Fedoraproject Fedora, Nlnetlabs Unbound. ## How do I fix CVE-2022-3204? Upgrade to a fixed version. ## Is CVE-2022-3204 being exploited? There is no known exploitation of CVE-2022-3204 in the wild and no public exploit code. ## Other vulnerabilities in Fedoraproject Fedora - [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild) - [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild) - [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild) - [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild) - [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2022-3204 and fix it if it is affected. What it is: CVE-2022-3204 is a high-severity denial of service vulnerability in Fedoraproject Fedora, published on 26 Sep 2022. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2022-3204 in the wild and no public exploit code. Affected product: Fedoraproject Fedora. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2022-3204/ (Markdown: https://insights.sbomify.com/CVE-2022-3204/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2022-3204 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-3204 - OSV: https://osv.dev/vulnerability/CVE-2022-3204 --- From sbomify Insights: https://insights.sbomify.com/CVE-2022-3204/ Summaries are generated and may contain mistakes; the official description above is the record.