CVE-2023-38710Network attack vector

Authenticated denial of service via REKEY protocol ID

Published Aug 25, 2023 · Updated Nov 26, 2024

Denial of service in Libreswan 3.20 through 4.11 allows remote authenticated users to restart the pluto daemon via an IKEv2 REKEY packet. An invalid protocol ID of 0 or 1 is copied into an INVALID_SPI response, whose outbound validation asserts that only ESP or AH is valid. Only an authenticated IKEv2 peer can reach the REKEY path, and repeated malformed packets can keep the VPN service unavailable.

CVSS severity6.5
Medium
EPSS probability0.81%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Libreswan 3.20 through 4.11 allows remote authenticated users to restart the pluto daemon via an IKEv2 REKEY packet. An invalid protocol ID of 0 or 1 is copied into an INVALID_SPI response, whose outbound validation asserts that only ESP or AH is valid. Only an authenticated IKEv2 peer can reach the REKEY path, and repeated malformed packets can keep the VPN service unavailable.

The record

CVE
CVE-2023-38710
Published
Aug 25, 2023
Updated
Nov 26, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 25, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 26, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5Oracle LinuxCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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