# CVE-2023-2829: Malformed NSEC records can cause named to terminate unexpectedly when synth-from-dnssec is enabled

> Remote attackers can crash the BIND DNS server by sending malformed NSEC records when the synth-from-dnssec option is enabled.

- **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:** 21 Jun 2023
- **Updated:** 13 Feb 2025
- **Also known as:** AZL-27305, GHSA-jhg8-766m-r23j

## What is CVE-2023-2829?

CVE-2023-2829 is a high-severity denial of service vulnerability in Isc Bind, published on 21 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A `named` instance configured to run as a DNSSEC-validating recursive resolver with the Aggressive Use of DNSSEC-Validated Cache (RFC 8198) option (`synth-from-dnssec`) enabled can be remotely terminated using a zone with a malformed NSEC record.
This issue affects BIND 9 versions 9.16.8-S1 through 9.16.41-S1 and 9.18.11-S1 through 9.18.15-S1.

## Which versions are affected by CVE-2023-2829?

It affects 7 products.


Products: Isc Bind, Netapp Active Iq Unified Manager, Netapp H300s Firmware, Netapp H410c Firmware, Netapp H410s Firmware, Netapp H500s Firmware, Netapp H700s Firmware.

## How do I fix CVE-2023-2829?

Apply the vendor's patch.

## Is CVE-2023-2829 being exploited?

There is no known exploitation of CVE-2023-2829 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-2023-2829 and fix it if it is affected.

What it is: CVE-2023-2829 is a high-severity denial of service vulnerability in Isc Bind, published on 21 Jun 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-2023-2829 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-2023-2829/ (Markdown: https://insights.sbomify.com/CVE-2023-2829/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-2829
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-2829
- OSV: https://osv.dev/vulnerability/CVE-2023-2829

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-2829/
Summaries are generated and may contain mistakes; the official description above is the record.