# CVE-2019-10190: Security feature bypass in knot-resolver

> Remote attackers can bypass DNSSEC validation for non-existence answers, allowing clients to receive unverified NXDOMAIN responses instead of errors.

- **Severity:** Medium 5.4 (`CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Jul 2019
- **Updated:** 13 Feb 2025
- **Also known as:** DEBIAN-CVE-2019-10190, GHSA-5pqr-9wpj-5m82, UBUNTU-CVE-2019-10190

## What is CVE-2019-10190?

CVE-2019-10190 is a medium-severity vulnerability in Fedoraproject Fedora, published on 16 Jul 2019. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was discovered in DNS resolver component of knot resolver through version 3.2.0 before 4.1.0 which allows remote attackers to bypass DNSSEC validation for non-existence answer. NXDOMAIN answer would get passed through to the client even if its DNSSEC validation failed, instead of sending a SERVFAIL packet. Caching is not affected by this particular bug but see CVE-2019-10191.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2019-10190?

It affects 2 products.


Products: Fedoraproject Fedora, Nic Knot Resolver.

## How do I fix CVE-2019-10190?

Upgrade to a fixed version.

## Is CVE-2019-10190 being exploited?

There is no known exploitation of CVE-2019-10190 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-2019-10190 and fix it if it is affected.

What it is: CVE-2019-10190 is a medium-severity vulnerability in Fedoraproject Fedora, published on 16 Jul 2019. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-10190 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-2019-10190/ (Markdown: https://insights.sbomify.com/CVE-2019-10190/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-10190
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-10190
- OSV: https://osv.dev/vulnerability/CVE-2019-10190

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-10190/
Summaries are generated and may contain mistakes; the official description above is the record.