← Vulnerability feed

Vulnerability record · CVE-2016-5361 · published 16 June 2016

CVE-2016-5361: Libreswan improper input validation vulnerability

Libreswan · Libreswan

programs/pluto/ikev1.c in libreswan before 3.17 retransmits in initial-responder states, which allows remote attackers to cause a denial of service (traffic amplification) via a spoofed UDP packet. NOTE: the original behavior complies with the IKEv1 protocol, but has a required security update from the libreswan vendor; as of 2016-06-10, it is expected that several other IKEv1 implementations will have vendor-required security updates, with separate CVE IDs assigned to each.

7.5 CVSS 3.0 High EPSS 2.7% · top 14.6% CWE-20 · Improper input validation
7.5CVSS 3.0 base score, v2 5.0
2.7%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
8References
17 Jun 2026Last modified by NVD

Description

programs/pluto/ikev1.c in libreswan before 3.17 retransmits in initial-responder states, which allows remote attackers to cause a denial of service (traffic amplification) via a spoofed UDP packet. NOTE: the original behavior complies with the IKEv1 protocol, but has a required security update from the libreswan vendor; as of 2016-06-10, it is expected that several other IKEv1 implementations will have vendor-required security updates, with separate CVE IDs assigned to each.

CVSS:3.0/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
http://rhn.redhat.com/errata/RHSA-2016-2603.html
http://www.openwall.com/lists/oss-security/2016/06/10/4
https://github.com/libreswan/libreswan/commit/152d6d95632d8b9477c170f1de99bcd86d7fb1d6 PatchVendor Advisory
https://lists.libreswan.org/pipermail/swan-dev/2016-March/001394.html
http://rhn.redhat.com/errata/RHSA-2016-2603.html
http://www.openwall.com/lists/oss-security/2016/06/10/4
https://github.com/libreswan/libreswan/commit/152d6d95632d8b9477c170f1de99bcd86d7fb1d6 PatchVendor Advisory
https://lists.libreswan.org/pipermail/swan-dev/2016-March/001394.html

Track CVE-2016-5361 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

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-2020-1763Libreswan out-of-bounds read vulnerabilityAn 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 us…EPSS 3.6%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%

Source: NIST National Vulnerability Database (record CVE-2016-5361), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.