CVE-2023-38712
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 · uneditedAn issue was discovered in Libreswan 3.x and 4.x before 4.12. When an IKEv1 ISAKMP SA Informational Exchange packet contains a Delete/Notify payload followed by further Notifies that act on the ISAKMP SA, such as a duplicated Delete/Notify message, a NULL pointer dereference on the deleted state causes the pluto daemon to crash and restart.
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 confidenceLibreswan pluto daemon contains a NULL pointer dereference vulnerability in IKEv1 ISAKMP SA Informational Exchange handling. When a Delete/Notify payload is followed by additional Notifies targeting the same ISAKMP SA (such as a duplicated Delete/Notify), the daemon attempts to dereference a pointer to already-deleted state information, causing the pluto daemon to crash and restart.
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>= 3.0, < 4.0>= 4.0, < 4.12CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/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 installed Libreswan versionRun 'ipsec --version' or check package manager (rpm -q libreswan, dpkg -l libreswan)Affected if Version is >= 3.0 and < 4.0, OR >= 4.0 and < 4.12
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Verify IKEv1 connections are in useRun 'ipsec status' or check /etc/ipsec.conf for 'keyexchange=ikev1' directives and active IKEv1 Security AssociationsAffected if IKEv1 connections are active or configured; the vulnerability only triggers with IKEv1 ISAKMP SA traffic
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Inspect pluto daemon for recent crashesCheck system logs (journalctl -u ipsec, /var/log/daemon.log, /var/log/messages) for pluto restarts or segfaults related to Delete/Notify payload handlingAffected if Pluto daemon has recently crashed and restarted with IKEv1 traffic present
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Check for Notify payload patterns in IKEv1 trafficMonitor or review IKEv1 traffic logs for Delete/Notify messages targeting existing ISAKMP SAs, especially duplicate Notify sequencesAffected if IKEv1 Delete/Notify traffic with repeated Notifies to the same SA is observed
You are affected if running a vulnerable Libreswan version (< 4.12, >= 3.0) AND IKEv1 connections are active, with potential daemon crashes observed in logs.
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 · scoped4.04.12
Upgrade to Libreswan version 4.12 or later to resolve this vulnerability. For systems that cannot immediately upgrade, consider restricting IKEv1 traffic at network boundaries as a compensating control.
Libreswan 4.12
- Upgrade Libreswan to version 4.12 or later
- Verify the upgrade completed successfully by checking the installed version (e.g., ipsec --version)
- Restart the pluto daemon to ensure the new version is running (systemctl restart ipsec or equivalent)
- Monitor the system logs for any unexpected crashes following the upgrade
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation3.0 h
- Testing4.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-38712 — 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-2023-38712 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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- Version or environment caveats, and links to real fixes
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