# CVE-2019-6476: An error in QNAME minimization code can cause BIND to exit with an assertion failure

> A defect in QNAME minimization allows a malicious forwarder to crash the BIND DNS server via assertion failure, requiring specific forwarding configurations.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/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:** 17 Oct 2019
- **Updated:** 16 Sep 2024
- **Also known as:** ALPINE-CVE-2019-6476, GHSA-7rr8-wvj2-chhv

## What is CVE-2019-6476?

CVE-2019-6476 is a medium-severity denial of service vulnerability in Isc Bind, published on 17 Oct 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A defect in code added to support QNAME minimization can cause named to exit with an assertion failure if a forwarder returns a referral rather than resolving the query. This affects BIND versions 9.14.0 up to 9.14.6, and 9.15.0 up to 9.15.4.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2019-6476?

It affects 1 product.


Products: Isc Bind.

## How do I fix CVE-2019-6476?

Upgrade to a fixed version.

## Is CVE-2019-6476 being exploited?

There is no known exploitation of CVE-2019-6476 in the wild and no public exploit code.

## Other vulnerabilities in Isc Bind

- [CVE-2008-0122](https://insights.sbomify.com/CVE-2008-0122/): Memory corruption in n/a (critical 10.0)
- [CVE-2001-0010](https://insights.sbomify.com/CVE-2001-0010/): Memory corruption in n/a (critical 10.0)
- [CVE-2001-0011](https://insights.sbomify.com/CVE-2001-0011/): Memory corruption in n/a (critical 10.0)
- [CVE-2001-0013](https://insights.sbomify.com/CVE-2001-0013/): Memory corruption in n/a (critical 10.0)
- [CVE-2000-1029](https://insights.sbomify.com/CVE-2000-1029/): Memory corruption in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-6476 and fix it if it is affected.

What it is: CVE-2019-6476 is a medium-severity denial of service vulnerability in Isc Bind, published on 17 Oct 2019. 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-2019-6476 in the wild and no public exploit code.

Affected product: Isc Bind. 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-2019-6476/ (Markdown: https://insights.sbomify.com/CVE-2019-6476/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-6476
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-6476
- OSV: https://osv.dev/vulnerability/CVE-2019-6476

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-6476/
Summaries are generated and may contain mistakes; the official description above is the record.