CVE-2023-41173
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 · uneditedAdGuard DNS before 2.2 allows remote attackers to cause a denial of service via malformed UDP packets.
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 confidenceAdGuard DNS versions prior to 2.2 are vulnerable to denial of service when processing specially crafted malformed UDP packets. Attackers can send malformed UDP packets to the DNS server causing it to become unavailable.
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< 2.2CVSS 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
- 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 checksWork through these to decide whether this CVE applies to you.
-
Verify AdGuard DNS is installedCheck for AdGuard DNS process or service running on the system using process listing commands (e.g., tasklist on Windows, ps on Linux) or check installed packagesAffected if AdGuard DNS process or service is found on the system
-
Determine installed AdGuard DNS versionRun the AdGuard DNS version command if available, or check the installed package version through system package managerAffected if Version returned is lower than 2.2 or cannot be determined to be 2.2 or higher
-
Confirm DNS service is listening on UDP port 53Check if the DNS service is bound to UDP port 53 using network status commands (e.g., netstat, ss, or nmap)Affected if AdGuard DNS is actively listening on UDP port 53 and serving DNS requests
-
Verify UDP traffic is exposed to untrusted networksReview firewall rules or network exposure settings to determine if UDP port 53 is accessible from external or untrusted networksAffected if UDP port 53 is accessible from network segments controlled by potential attackers
The environment is affected if AdGuard DNS version is installed and is lower than 2.2, and the DNS service is accepting UDP traffic.
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 · scoped2.2
Upgrade AdGuard DNS to version 2.2 or later to remediate this vulnerability. Additionally, network-level filtering or rate limiting for UDP traffic to DNS servers can provide defense-in-depth.
AdGuard DNS 2.2
- 1. Back up current AdGuard DNS configuration and data
- 2. Consult AdGuard DNS documentation for upgrade procedures specific to your deployment method
- 3. Upgrade AdGuard DNS to version 2.2 or later
- 4. Verify the service is running correctly after upgrade
- 5. Test that DNS resolution is functioning properly
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 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 $1,696.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-41173 — 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-2023-41173 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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