# CVE-2018-1110: Denial of service in knot-resolver

> Attackers can cause denial of service in Knot Resolver by sending malformed DNS messages, affecting DNS infrastructure availability.

- **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:** 30 Mar 2021
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-1110, GHSA-gv92-3p38-6rrw, UBUNTU-CVE-2018-1110

## What is CVE-2018-1110?

CVE-2018-1110 is a high-severity denial of service vulnerability in knot-resolver, published on 30 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw was found in knot-resolver before version 2.3.0. Malformed DNS messages may cause denial of service.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2018-1110?

It affects 1 product.


Products: Nic Knot Resolver.

## How do I fix CVE-2018-1110?

Upgrade to a fixed version.

## Is CVE-2018-1110 being exploited?

There is no known exploitation of CVE-2018-1110 in the wild and no public exploit code.

## Other vulnerabilities in knot-resolver

- [CVE-2023-46317](https://insights.sbomify.com/CVE-2023-46317/): Denial of service in n/a (high 7.5)
- [CVE-2023-26249](https://insights.sbomify.com/CVE-2023-26249/): Denial of service in n/a (high 7.5)
- [CVE-2021-40083](https://insights.sbomify.com/CVE-2021-40083/): Denial of service in n/a (high 7.5)
- [CVE-2020-12667](https://insights.sbomify.com/CVE-2020-12667/): Denial of service in n/a (high 7.5)
- [CVE-2018-10920](https://insights.sbomify.com/CVE-2018-10920/): Other in knot-resolver (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-1110 and fix it if it is affected.

What it is: CVE-2018-1110 is a high-severity denial of service vulnerability in knot-resolver, published on 30 Mar 2021. 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-2018-1110 in the wild and no public exploit code.

Affected product: knot-resolver. 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-2018-1110/ (Markdown: https://insights.sbomify.com/CVE-2018-1110/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-1110
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-1110
- OSV: https://osv.dev/vulnerability/CVE-2018-1110

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-1110/
Summaries are generated and may contain mistakes; the official description above is the record.