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Vulnerability record · CVE-2020-1763 · published 12 May 2020

CVE-2020-1763: Libreswan out-of-bounds read vulnerability

Libreswan · Libreswan

An out-of-bounds buffer read flaw was found in the pluto daemon of libreswan from versions 3.27 till 3.31 where, an unauthenticated attacker could use this flaw to crash libreswan by sending specially-crafted IKEv1 Informational Exchange packets. The daemon respawns after the crash.

7.5 CVSS 3.1 High EPSS 3.6% · top 11.0% CWE-125 · Out-of-bounds read
7.5CVSS 3.1 base score, v2 5.0
3.6%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
16References
17 Jun 2026Last modified by NVD

Description

An out-of-bounds buffer read flaw was found in the pluto daemon of libreswan from versions 3.27 till 3.31 where, an unauthenticated attacker could use this flaw to crash libreswan by sending specially-crafted IKEv1 Informational Exchange packets. The daemon respawns after the crash.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://bugzilla.redhat.com/show_bug.cgi?id=1813329 Issue TrackingThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1763 Issue TrackingThird Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-379803.pdf Third Party Advisory
https://github.com/libreswan/libreswan/commit/471a3e41a449d7c753bc4edbba4239501bb62ba8 PatchThird Party Advisory
https://libreswan.org/security/CVE-2020-1763/CVE-2020-1763.txt PatchVendor Advisory
https://security.gentoo.org/glsa/202007-21 Third Party Advisory
https://us-cert.cisa.gov/ics/advisories/icsa-21-040-04 Third Party AdvisoryUS Government Resource
https://www.debian.org/security/2020/dsa-4684 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1813329 Issue TrackingThird Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-1763 Issue TrackingThird Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-379803.pdf Third Party Advisory
https://github.com/libreswan/libreswan/commit/471a3e41a449d7c753bc4edbba4239501bb62ba8 PatchThird Party Advisory
https://libreswan.org/security/CVE-2020-1763/CVE-2020-1763.txt PatchVendor Advisory
https://security.gentoo.org/glsa/202007-21 Third Party Advisory
https://us-cert.cisa.gov/ics/advisories/icsa-21-040-04 Third Party AdvisoryUS Government Resource
https://www.debian.org/security/2020/dsa-4684 Third Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.3CVE-2013-7283Libreswan race condition vulnerabilityRace condition in the libreswan.spec files for Red Hat Enterprise Linux (RHEL) and Fedora packages in libreswan 3.6 has unspecified impact and attack…EPSS 1.6%7.5CVE-2026-12413Libreswan vulnerabilityAn invalidly formatted IKEv2 fragment causes the Libreswan pluto daemon to crash and restart. Continued exploitation would cause a denial of service.…EPSS 0.60%7.5CVE-2023-30570Libreswan uncontrolled resource consumption vulnerabilitypluto in Libreswan before 4.11 allows a denial of service (responder SPI mishandling and daemon crash) via unauthenticated IKEv1 Aggressive Mode pack…EPSS 1.2%7.5CVE-2023-2295Libreswan uncontrolled resource consumption vulnerabilityA vulnerability was found in the libreswan library. This security issue occurs when an IKEv1 Aggressive Mode packet is received with only unacceptabl…EPSS 1.6%7.5CVE-2022-23094Libreswan null pointer dereference vulnerabilityLibreswan 4.2 through 4.5 allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted IKEv1 packet…EPSS 2.5%7.5CVE-2019-12312Libreswan null pointer dereference vulnerabilityIn Libreswan 3.27 an assertion failure can lead to a pluto IKE daemon restart. An attacker can trigger a NULL pointer dereference by initiating an IK…EPSS 2.7%7.5CVE-2016-5391Libreswan null pointer dereference vulnerabilitylibreswan before 3.18 allows remote attackers to cause a denial of service (NULL pointer dereference and pluto daemon restart).EPSS 3.0%7.5CVE-2016-5361Libreswan improper input validation vulnerabilityprograms/pluto/ikev1.c in libreswan before 3.17 retransmits in initial-responder states, which allows remote attackers to cause a denial of service (…EPSS 2.7%

Source: NIST National Vulnerability Database (record CVE-2020-1763), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.