FedoraOperating system · Fedoraproject
CVE-2022-30698
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedNLnet 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceUnbound DNS resolver up to 1.16.1 is vulnerable to a 'ghost domain names' attack where a rogue nameserver can keep a domain resolvable by continuously updating child delegation information in Unbound's cache before expiry, exploiting Unbound's child-centric resolver design that doesn't validate parent delegation records.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FedoraOperating system
= 35= 36< 1.16.2CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check if Unbound DNS resolver is installedRun 'rpm -qa | grep -i unbound' on Fedora systems, or 'unbound -V' on any system to see version informationAffected if Unbound is installed and running as a DNS resolver
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Determine the exact Unbound versionRun 'unbound -V 2>&1 | head -1' or check the package version with 'rpm -q unbound'Affected if Version displayed is below 1.16.2 (for example, 1.16.1, 1.16.0, or any 1.x version less than 1.16.2)
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Confirm Unbound is in use as a DNS resolverCheck if the unbound service is active and listening on port 53: 'systemctl status unbound' and 'ss -tulpn | grep :53'Affected if Unbound service is running and handling DNS queries (this makes the vulnerability exploitable)
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Verify Fedora version if applicableIf running on Fedora, check with 'cat /etc/fedora-release' or 'rpm -q fedora-release'Affected if Running Fedora 35 or 36 which ship the vulnerable Unbound version
A system is affected if it runs Unbound version 1.16.1 or earlier as an active DNS resolver, or runs Fedora 35/36 with the packaged Unbound version below 1.16.2.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped1.16.2
Upgrade Unbound to version 1.16.2 or later which implements validation of parent delegation records before using cached delegation information.
Unbound >= 1.16.2
- Check current Unbound version using: `unbound -V` or `unbound-control version`
- For Fedora systems: run `sudo dnf update unbound` to upgrade to the fixed version (1.16.2 or later)
- For other systems: download and install Unbound 1.16.2 or later from the official NLnet Labs source (https://www.nlnetlabs.nl/projects/unbound/download/)
- Verify the installed version is 1.16.2 or later using `unbound -V`
- Restart the Unbound service: `sudo systemctl restart unbound`
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Fedora
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-30698 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2022-30698 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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