LibreswanApplication

CVE-2024-3652

MEDIUM · 6.5 CVSS v3.1 Published 2024-04-11
Fix available
A fix is available. Upgrade to 4.15 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable 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
The Libreswan Project was notified of an issue causing libreswan to restart when using IKEv1 without specifying an esp= line. When the peer requests AES-GMAC, libreswan's default proposal handler causes an assertion failure and crashes and restarts. IKEv2 connections are not affected.

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

Libreswan IKEv1 connections without an explicit esp= configuration line trigger an assertion failure in the default proposal handler when the peer requests AES-GMAC, causing the daemon to crash and restart. IKEv2 connections are unaffected.

MitigationConfigure an explicit esp= line in the IKEv1 connection definitions to bypass the default proposal handler that triggers the assertion failure.

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
LibreswanApplication
Affected:>= 3.22, < 4.15

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
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 checks

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

  1. Check installed Libreswan version
    Run 'ipsec --version' or 'rpm -q libreswan' or 'dpkg -l | grep libreswan' to obtain the installed version number
    Affected if Version is 3.22 or higher but lower than 4.15
  2. Locate IKEv1 connection definitions
    Examine /etc/ipsec.conf and files in /etc/ipsec.d/ for connection definitions. IKEv1 connections are those without 'ikev2=yes' or with explicit IKEv1 settings like 'phase1alg' or 'keyexchange=ikev1'
    Affected if Any IKEv1 connections exist in the configuration
  3. Identify connections without explicit esp= line
    Within each IKEv1 connection definition, search for the 'esp=' directive. Connections missing this line rely on the default proposal handler
    Affected if Any IKEv1 connection lacks an explicit 'esp=' configuration line
  4. Verify AES-GMAC is in default proposals
    Review /etc/ipsec.conf for 'esp' defaults or check swanctl configuration if used. AES-GMAC may be included in default ESP proposals on systems with AES-GCM support
    Affected if AES-GMAC could be selected as the default ESP algorithm for connections without explicit esp=

If Libreswan version is between 3.22 and 4.14 and there are IKEv1 connections lacking explicit esp= configuration, the environment is affected by this vulnerability and will crash when a peer proposes AES-GMAC.

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 4.15 or later
Fixed in 4.15
Interim mitigation

Configure an explicit esp= line in the IKEv1 connection definitions to bypass the default proposal handler that triggers the assertion failure.

Recommended fix High confidence

4.15

  1. 1. Check current Libreswan version using: ipsec --version
  2. 2. Upgrade Libreswan to version 4.15 or later using your system's package manager (e.g., yum update libreswan or apt-get install libreswan)
  3. 3. After upgrade, restart the ipsec service: systemctl restart ipsec
  4. 4. Verify the new version is installed: ipsec --version

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

Fix this in Libreswan Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,376.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2024-3652 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-3652 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
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