RHEL 7 : libreswan (RHSA-2015:1979)

high Nessus Plugin ID 86744

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Synopsis

The remote Red Hat host is missing a security update for libreswan.

Description

The remote Redhat Enterprise Linux 7 host has a package installed that is affected by a vulnerability as referenced in the RHSA-2015:1979 advisory.

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).

A flaw was discovered in the way Libreswan's IKE daemon processed IKE KE payloads. A remote attacker could send specially crafted IKE payload with a KE payload of g^x=0 that, when processed, would lead to a denial of service (daemon crash). (CVE-2015-3240)

This issue was discovered by Paul Wouters of Red Hat.

Note: Please note that when upgrading from an earlier version of Libreswan, the existing CA certificates in the /etc/ipsec.d/cacerts/ directory and the existing certificate revocation list (CRL) files from the /etc/ipsec.d/crls/ directory are automatically imported into the NSS database. Once completed, these directories are no longer used by Libreswan. To install new CA certificates or new CRLS, the certutil and crlutil commands must be used to import these directly into the Network Security Services (NSS) database.

This update also adds the following enhancements:

* This update adds support for RFC 7383 IKEv2 Fragmentation, RFC 7619 Auth Null and ID Null, INVALID_KE renegotiation, CRL and OCSP support via NSS, AES_CTR and AES_GCM support for IKEv2, CAVS testing for FIPS compliance.

In addition, this update enforces FIPS algorithms restrictions in FIPS mode, and runs Composite Application Validation System (CAVS) testing for FIPS compliance during package build. A new Cryptographic Algorithm Validation Program (CAVP) binary can be used to re-run the CAVS tests at any time. Regardless of FIPS mode, the pluto daemon runs RFC test vectors for various algorithms.

Furthermore, compiling on all architectures now enables the -Werror GCC option, which enhances the security by making all warnings into errors.
(BZ#1263346)

* This update also fixes several memory leaks and introduces a sub-second packet retransmit option. (BZ#1268773)

* This update improves migration support from Openswan to Libreswan.
Specifically, all Openswan options that can take a time value without a suffix are now supported, and several new keywords for use in the /etc/ipsec.conf file have been introduced. See the relevant man pages for details. (BZ#1268775)

* With this update, loopback support via the loopback= option has been deprecated. (BZ#1270673)

All Libreswan users are advised to upgrade to these updated packages, which contain backported patches to correct these issues and add these enhancements.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise 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.

Solution

Update the RHEL libreswan package based on the guidance in RHSA-2015:1979.

Plugin Details

Severity: High

ID: 86744

File Name: redhat-RHSA-2015-1979.nasl

Version: 2.14

Type: local

Agent: unix

Family: Red Hat Local Security Checks

Published: 11/5/2015

Updated: 4/15/2025

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.6

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.2

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2015-3240

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:libreswan, cpe:/o:redhat:enterprise_linux:7

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Ease: No known exploits are available

Patch Publication Date: 11/3/2015

Vulnerability Publication Date: 11/9/2015

Reference Information

CVE: CVE-2015-3240

CWE: 617

RHSA: 2015:1979

Detections

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