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DnsserverApplication · Technitium

CVE-2023-28456

HIGH · 7.5 CVSS v3.1 Published 2024-09-18
Fix available
A fix is available. Upgrade to after 11.0.2 or later.
See remediation →
84/100
Remediation priority · High
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 through 11.0.2. It enables attackers to launch amplification attacks (3 times more than other "golden model" software like BIND) and cause potential DoS.

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 · moderate confidence

Technitium DNS Server through version 11.0.2 contains a DNS amplification vulnerability that allows attackers to leverage the server to launch reflected denial-of-service attacks. The software exhibits a 3x higher amplification factor compared to standard DNS implementations like BIND, enabling attackers to amplify their attack traffic and overwhelm target systems.

MitigationUpdate Technitium DNS Server to the latest version beyond 11.0.2 and implement DNS response rate limiting, disable open recursion, and configure proper ACLs to prevent unauthorized use as an amplification reflector.

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
DnsserverApplication
Affected:<= 11.0.2

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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. Identify Technitium DNS Server version
    Check the installed version by looking at the application, its installer, or the running service. On Windows, check the program files directory or installed programs list. On Linux, check the package or the /opt/dns directory. The version is typically displayed in the web admin panel under 'System' or 'About'.
    Affected if The installed version is 11.0.2 or lower
  2. Verify DNS service is internet-facing
    Check which IP addresses the DNS service is bound to. Review the DNS server configuration or use netstat -anp | grep :53 to see listening addresses. Look at the network interface bindings in the DNS server admin panel under 'Network' or 'Interfaces'.
    Affected if The DNS service is bound to a public/external IP address accessible from the internet
  3. Confirm recursion is enabled
    Check the DNS server settings for recursion or resolver configuration. In the admin panel, go to 'Resolver' settings and verify if 'Allow Recursion' or similar option is enabled. Check configuration files for 'allow-recursion' or 'recursion' settings.
    Affected if Recursion is enabled and the server will resolve queries for any client

You are affected if you run Technitium DNS Server version 11.0.2 or earlier with the DNS service exposed to the internet and recursion enabled, allowing your server to be used as a DNS amplification reflector.

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 11.0.2
Interim mitigation

Update Technitium DNS Server to the latest version beyond 11.0.2 and implement DNS response rate limiting, disable open recursion, and configure proper ACLs to prevent unauthorized use as an amplification reflector.

Recommended fix High confidence

Technitium DNS Server version 11.0.3 or later

  1. Back up the current Technitium DNS Server configuration and data
  2. Download the latest version of Technitium DNS Server from the official source (technitium.com)
  3. Stop the current DNS Server service
  4. Install the updated version
  5. Start the DNS Server service
  6. Verify the server is functioning correctly and responding to queries

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

Fix this in Dnsserver Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

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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-2023-28456 in production — separate from our analysis above.

No notes yet

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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