dbcve.org
Enterprise LinuxOperating system · Redhat

CVE-2023-2295

HIGH · 7.5 CVSS v3.1 Published 2023-05-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
A vulnerability was found in the libreswan library. This security issue occurs when an IKEv1 Aggressive Mode packet is received with only unacceptable crypto algorithms, and the response packet is not sent with a zero responder SPI. When a subsequent packet is received where the sender reuses the libreswan responder SPI as its own initiator SPI, the pluto daemon state machine crashes. No remote code execution is possible. This CVE exists because of a CVE-2023-30570 security regression for libreswan package in Red Hat Enterprise Linux 8.8 and Red Hat Enterprise Linux 9.2.

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

A vulnerability in libreswan's IKEv1 Aggressive Mode handling causes a pluto daemon state machine crash when a packet with unacceptable crypto algorithms is received and the response fails to use a zero responder SPI. Subsequent packets that reuse the libreswan responder SPI as an initiator SPI trigger the crash, resulting in denial of service.

MitigationApply vendor security updates for the libreswan package in RHEL 8.8 and RHEL 9.2 to address this regression from CVE-2023-30570. Network-based filtering of IKE traffic can provide temporary mitigation until patches are applied.

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
Affected:= 8.0= 9.0
Enterprise Linux EusOperating system
Affected:= 8.8= 9.2
Enterprise Linux Server AusOperating system
Affected:= 8.8= 9.2
Enterprise Linux Server TusOperating system
Affected:= 8.8
LibreswanApplication
Affected:= 4.9-1.el8= 4.9-1.el9

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. Verify libreswan is installed
    Run 'rpm -q libreswan' or check for the existence of /usr/sbin/pluto
    Affected if libreswan is not installed, the system is not affected by this vulnerability in libreswan
  2. Check installed libreswan version
    Run 'rpm -q --qf '%{VERSION}-%{RELEASE}' libreswan' to get the exact version string, then compare against the affected versions 4.9-1.el8 and 4.9-1.el9
    Affected if the installed version matches 4.9-1.el8, 4.9-1.el9, or falls within the RHEL 8.0-9.2 ranges mentioned for this CVE, the system could be affected
  3. Confirm IKEv1 Aggressive Mode is configured
    Check /etc/ipsec.conf for 'aggrmode=yes' in any connection definition, or inspect /var/log/pluto.log for 'aggressive mode' related configuration
    Affected if IKEv1 Aggressive Mode is not configured or enabled, the specific crash condition cannot be triggered
  4. Verify pluto daemon is running
    Run 'systemctl status pluto' or 'ps aux | grep pluto' to confirm the IPSec daemon is active
    Affected if the pluto daemon is not running, the crash cannot occur even if vulnerable code is present
  5. Check for recent pluto crashes or restarts
    Review 'journalctl -u pluto -n 50' or /var/log/messages for pluto daemon crash indicators or unexpected restarts around IKEv1 Aggressive Mode exchanges
    Affected if the pluto daemon has crashed or restarted unexpectedly after processing IKEv1 aggressive mode packets, this indicates possible exploitation of this vulnerability

The system is affected if libreswan version 4.9-1.el8 or 4.9-1.el9 (or corresponding RHEL 8.0-9.2 packages) is installed with IKEv1 Aggressive Mode enabled and the pluto daemon is running.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor security updates for the libreswan package in RHEL 8.8 and RHEL 9.2 to address this regression from CVE-2023-30570. Network-based filtering of IKE traffic can provide temporary mitigation until patches are applied.

Recommended fix High confidence

libreswan version higher than 4.9-1.el8/el9 ( consult Red Hat RHSA advisory for exact version )

  1. 1. Identify the current installed version of libreswan: rpm -qa | grep libreswan
  2. 2. Update the package repository metadata: dnf check-update
  3. 3. Apply the security update for libreswan: dnf update libreswan
  4. 4. Verify the updated version is installed: rpm -qa | grep libreswan
  5. 5. Restart the ipsec service to apply changes: systemctl restart ipsec
Caveat Updates may require service restart; test in staging environment first

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

Fix this in Enterprise Linux Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,760
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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-2023-2295 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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