# CVE-2022-3924: named configured to answer from stale cache may terminate unexpectedly at recursive-clients soft quota

> A race condition in BIND 9 resolvers with stale answers enabled can cause an assertion failure and unexpected termination under high recursive load.

- **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:** 25 Jan 2023
- **Updated:** 31 Mar 2025
- **Also known as:** ALPINE-CVE-2022-3924, AZL-13227, DEBIAN-CVE-2022-3924, GHSA-29px-hvx8-j7xf, UBUNTU-CVE-2022-3924

## What is CVE-2022-3924?

CVE-2022-3924 is a high-severity vulnerability in Isc Bind, published on 25 Jan 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

This issue can affect BIND 9 resolvers with `stale-answer-enable yes;` that also make use of the option `stale-answer-client-timeout`, configured with a value greater than zero.

If the resolver receives many queries that require recursion, there will be a corresponding increase in the number of clients that are waiting for recursion to complete. If there are sufficient clients already waiting when a new client query is received so that it is necessary to SERVFAIL the longest waiting client (see BIND 9 ARM `recursive-clients` limit and soft quota), then it is possible for a race to occur between providing a stale answer to this older client and sending an early timeout SERVFAIL, which may cause an assertion failure.
This issue affects BIND 9 versions 9.16.12 through 9.16.36, 9.18.0 through 9.18.10, 9.19.0 through 9.19.8, and 9.16.12-S1 through 9.16.36-S1.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2022-3924?

It affects 1 product.


Products: Isc Bind.

## How do I fix CVE-2022-3924?

Upgrade to a fixed version.

## Is CVE-2022-3924 being exploited?

There is no known exploitation of CVE-2022-3924 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-2022-3924 and fix it if it is affected.

What it is: CVE-2022-3924 is a high-severity vulnerability in Isc Bind, published on 25 Jan 2023. 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-2022-3924 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-2022-3924/ (Markdown: https://insights.sbomify.com/CVE-2022-3924/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-3924
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-3924
- OSV: https://osv.dev/vulnerability/CVE-2022-3924

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-3924/
Summaries are generated and may contain mistakes; the official description above is the record.