CVE-2023-2295Network attack vector

Remote daemon crash via reused responder SPI

Published May 17, 2023 · Updated Jan 22, 2025

Denial of service in Libreswan 4.9-1.el8 and 4.9-1.el9 allows remote attackers to crash the pluto daemon with crafted IKEv1 packets. When pluto rejects all proposed algorithms, its Aggressive Mode reply retains a nonzero responder SPI; accepting that reused SPI in the next initiator packet drives the state machine into a crash. An exposed IKEv1 Aggressive Mode responder is required, and the reported impact is a daemon crash without code execution.

CVSS severity7.5
High
EPSS probability1.58%
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 4.9-1.el8 and 4.9-1.el9 allows remote attackers to crash the pluto daemon with crafted IKEv1 packets. When pluto rejects all proposed algorithms, its Aggressive Mode reply retains a nonzero responder SPI; accepting that reused SPI in the next initiator packet drives the state machine into a crash. An exposed IKEv1 Aggressive Mode responder is required, and the reported impact is a daemon crash without code execution.

The record

CVE
CVE-2023-2295
Published
May 17, 2023
Updated
Jan 22, 2025
Vendor
The Libreswan Project
Product
Libreswan
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 17, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 22, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Affects libreswan v4.9-1.el8 and libreswan v4.9-1.el9, Fixed in libreswan v4.9-3.el8_8 and libreswan v4.9-4.el9_2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Libreswan Project · Libreswanversion=Affects libreswan v4.9-1.el8 and libreswan v4.9-1.el9, Fixed in libreswan v4.9-3.el8_8 and libreswan v4.9-4.el9_2

Published CVSS scores

7.5Red Hat, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

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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