Enterprise LinuxOperating system · Redhat
CVE-2023-38472
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 · uneditedA vulnerability was found in Avahi. A reachable assertion exists in the avahi_rdata_parse() function.
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 confidenceA reachable assertion in Avahi's avahi_rdata_parse() function can be triggered by specially crafted mDNS/DNS-SD packets, causing the Avahi daemon to crash. This is a denial-of-service vulnerability stemming from insufficient validation in the rdata parsing logic.
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
Enterprise LinuxOperating system
= 8.0= 9.0< 0.9CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/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.
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Check if Avahi is installedRun 'rpm -qa | grep -i avahi' (RHEL) or 'dpkg -l | grep avahi' (Debian/Ubuntu) to list installed Avahi packagesAffected if No Avahi package is installed means not affected
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Determine installed Avahi versionRun 'rpm -q avahi' (RHEL) or 'dpkg -s avahi-daemon' (Debian/Ubuntu) to get the exact version number, then compare against the affected range (versions below 0.9, or RHEL 8.0/9.0 specifically)Affected if Installed version is below 0.9, or running RHEL 8.0/9.0 with any Avahi version, indicates potential vulnerability
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Verify if Avahi daemon is runningRun 'systemctl status avahi-daemon' or check process list with 'ps aux | grep avahi-daemon' to see if the daemon is activeAffected if Avahi daemon is running means the vulnerability can be triggered; if daemon is disabled/not running, the crash cannot occur
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Check if mDNS/avahi is network-enabledInspect /etc/avahi/avahi-daemon.conf for 'enable-reflector=yes' or check if port 5353/udp is open and listening with 'ss -ulpn | grep 5353'Affected if mDNS multicast is enabled and accessible on the network provides the attack surface for malicious packets
A system is affected if it runs Avahi daemon with version below 0.9 (or RHEL 8.0/9.0) and has mDNS network functionality enabled, allowing external mDNS packets to reach the daemon.
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.
From vendor data0.9
Apply the Avahi security update that addresses the assertion vulnerability. If no patch is available, consider network-level filtering to restrict mDNS traffic to trusted sources.
Fix this in Enterprise Linux
Scoped from the published advisory
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-38472 — 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-2023-38472 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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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
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