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.

The remote Redhat Enterprise Linux 5 host has one or more packages installed that are affected by multiple vulnerabilities that have been acknowledged by the vendor but will not be patched.

  - IKEv1: IKEv1 protocol vulnerability in the authentication mode with pre-shared keys in the main mode of     operation (CVE-2018-5389)

  - The pluto IKE daemon in libreswan before 3.15 and Openswan before 2.6.45, when built with NSS, allows     remote attackers to cause a denial of service (assertion failure and daemon restart) via a zero DH g^x     value in a KE payload in a IKE packet. (CVE-2015-3240)

  - 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. (CVE-2016-5361)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package is installed.

The remote Redhat Enterprise Linux 6 host has one or more packages installed that are affected by multiple vulnerabilities that have been acknowledged by the vendor but will not be patched.

  - IKEv1: IKEv1 protocol vulnerability in the authentication mode with pre-shared keys in the main mode of     operation (CVE-2018-5389)

  - The pluto IKE daemon in libreswan before 3.15 and Openswan before 2.6.45, when built with NSS, allows     remote attackers to cause a denial of service (assertion failure and daemon restart) via a zero DH g^x     value in a KE payload in a IKE packet. (CVE-2015-3240)

  - 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. (CVE-2016-5361)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package is installed.

According to the version of the libreswan package installed, the EulerOS installation on the remote host is affected by the following vulnerability :

  - A traffic amplification flaw was found in the Internet     Key Exchange version 1 (IKEv1) protocol. A remote     attacker could use a libreswan server with IKEv1     enabled in a network traffic amplification denial of     service attack against other hosts on the network by     sending UDP packets with a spoofed source address to     that server. (CVE-2016-5361)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Security Fix(es) :

  - A traffic amplification flaw was found in the Internet     Key Exchange version 1 (IKEv1) protocol. A remote     attacker could use a libreswan server with IKEv1 enabled     in a network traffic amplification denial of service     attack against other hosts on the network by sending UDP     packets with a spoofed source address to that server.
    (CVE-2016-5361)

Additional Changes :

An update for libreswan is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Libreswan is an implementation of IPsec & IKE for Linux. IPsec is the Internet Protocol Security and uses strong cryptography to provide both authentication and encryption services. These services allow you to build secure tunnels through untrusted networks such as virtual private network (VPN).

Security Fix(es) :

* A traffic amplification flaw was found in the Internet Key Exchange version 1 (IKEv1) protocol. A remote attacker could use a libreswan server with IKEv1 enabled in a network traffic amplification denial of service attack against other hosts on the network by sending UDP packets with a spoofed source address to that server. (CVE-2016-5361)

Additional Changes :

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.3 Release Notes linked from the References section.

The remote Oracle Linux 7 host has a package installed that is affected by a vulnerability as referenced in the ELSA-2016-2603 advisory.

    - Resolves: rhbz#1344567 CVE-2016-5361 libreswan: IKEv1 protocol is vulnerable to DoS amplification attack

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
198929	RHEL 5 : openswan (Unpatched Vulnerability)	Nessus	Red Hat Local Security Checks	medium
198920	RHEL 6 : openswan (Unpatched Vulnerability)	Nessus	Red Hat Local Security Checks	medium
99838	EulerOS 2.0 SP1 : libreswan (EulerOS-SA-2016-1078)	Nessus	Huawei Local Security Checks	high
95845	Scientific Linux Security Update : libreswan on SL7.x x86_64 (20161103)	Nessus	Scientific Linux Local Security Checks	high
95349	CentOS 7 : libreswan (CESA-2016:2603)	Nessus	CentOS Local Security Checks	high
94722	Oracle Linux 7 : libreswan (ELSA-2016-2603)	Nessus	Oracle Linux Local Security Checks	high
94566	RHEL 7 : libreswan (RHSA-2016:2603)	Nessus	Red Hat Local Security Checks	high

Detections

Analytics

CVE-2016-5361

high

Tenable Plugins

medium

medium

high

high

high

high

high