dbcve.org
Dns ServerApplication · Technitium

CVE-2022-30257

CRITICAL · 9.8 CVSS v3.1 Published 2022-11-21
Fix available
A fix is available. Upgrade to after 8.0.2 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

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 · unedited
An issue was discovered in Technitium DNS Server through 8.0.2 that allows variant V1 of unintended domain name resolution. A revoked domain name can still be resolvable for a long time, including expired domains and taken-down malicious domains. The effects of an exploit would be widespread and highly impactful, because the exploitation conforms to de facto DNS specifications and operational practices, and overcomes current mitigation patches for "Ghost" domain names.

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 confidence

Technitium DNS Server through 8.0.2 contains a vulnerability allowing revoked domain names (expired, taken-down, or maliciously controlled) to continue resolving due to improper DNS cache validation. This is a variant V1 of the 'Ghost' domain name problem that bypasses existing mitigation patches, causing the server to serve stale or malicious DNS records for domains that should no longer be resolvable.

MitigationUpgrade Technitium DNS Server to the latest patched version and implement aggressive cache expiration policies for domains at risk of revocation. Consider implementing DNS response validation against known blocklists of revoked domains.

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
Dns ServerApplication
Affected:<= 8.0.2

CVSS 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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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 checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Technitium DNS Server installation
    Check if the Technitium DNS Server service or process is running on the system. Look for 'DnsServer' process or check installed programs list.
    Affected if Technitium DNS Server is installed and running on the system.
  2. Identify installed version
    Access the DNS server web administration panel (typically http://localhost:5380) and check the version displayed in the UI, or check the application's about/logs for the version number.
    Affected if The installed version is 8.0.2 or lower.
  3. Verify DNS caching is enabled
    Check the DNS server configuration files or web interface settings for DNS cache settings. Look for cache-related configuration options in the DNS app settings.
    Affected if DNS caching is enabled in the server configuration.
  4. Inspect DNS zone configurations
    Review the DNS zones configured in the server. Check if forward zones or conditional forwarders are defined that could serve stale records for revoked domains.
    Affected if The server hosts custom DNS zones or forwarders that rely on caching.
  5. Test resolution of potentially revoked domains
    Query the DNS server for domain names known to have been revoked, expired, or taken down. Compare responses against current valid DNS records.
    Affected if The server returns IP addresses for domains that should no longer resolve or have changed records.

A system is affected if it runs Technitium DNS Server version 8.0.2 or lower with DNS caching enabled and is resolving stale records for revoked domains.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to a release after 8.0.2
Interim mitigation

Upgrade Technitium DNS Server to the latest patched version and implement aggressive cache expiration policies for domains at risk of revocation. Consider implementing DNS response validation against known blocklists of revoked domains.

Recommended fix High confidence

Technitium DNS Server 8.1 or later

  1. 1. Backup current DNS server configuration and zone data
  2. 2. Download Technitium DNS Server version 8.1 or later from the official GitHub releases page
  3. 3. Stop the current DNS Server service
  4. 4. Install the updated version (8.1 or newer)
  5. 5. Start the DNS Server service
  6. 6. Verify that the DNS server is functioning correctly and resolving domains as expected
  7. 7. Test that previously revoked/expired domains are no longer being resolved
Caveat Review release notes for any configuration or feature changes between 8.0.2 and the target upgrade version

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Dns Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,808.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-30257 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data