libreswan 3.9 through 3.12 allows remote attackers to cause a denial of service (daemon restart) via an IKEv1 packet with (1) unassigned bits set in the IPSEC DOI value or (2) the next payload value set to ISAKMP_NEXT_SAK.

The remote host is affected by the vulnerability described in GLSA-201603-13 (Libreswan: Multiple Vulnerabilities)

    The pluto IKE daemon in Libreswan, 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.
      Additionally, remote attackers could cause a Denial of Service (daemon       restart) via an IKEv1 packet with (1) unassigned bits set in the IPSEC       DOI value or (2) the next payload value set to ISAKMP_NEXT_SAK.
  Impact :

    Remote attackers could possibly cause Denial of Service.
  Workaround :

    There is no known workaround at this time.

A flaw was discovered in the way Libreswan's IKE daemon processed certain IKEv1 payloads. A remote attacker could send specially crafted IKEv1 payloads that, when processed, would lead to a denial of service (daemon crash). (CVE-2015-3204)

This update fixes the following bugs :

  - Previously, the programs/pluto/state.h and     programs/pluto/kernel_netlink.c files had a maximum     SELinux context size of 257 and 1024 respectively. These     restrictions set by libreswan limited the size of the     context that can be exchanged by pluto (the IPSec     daemon) when using a Labeled Internet Protocol Security     (IPsec). The SElinux labels for Labeled IPsec have been     extended to 4096 bytes and the mentioned restrictions no     longer exist.

  - On some architectures, the kernel AES_GCM IPsec     algorithm did not work properly with acceleration     drivers. On those kernels, some acceleration modules are     added to the modprobe blacklist. However, Libreswan was     ignoring this blacklist, leading to AES_GCM failures.
    This update adds support for the module blacklist to the     libreswan packages and thus prevents the AES_GCM     failures from occurring.

  - An IPv6 issue has been resolved that prevented ipv6-icmp     Neighbour Discovery from working properly once an IPsec     tunnel is established (and one endpoint reboots). When     upgrading, ensure that /etc/ipsec.conf is loading all     /etc/ipsec.d/*conf files using the /etc/ipsec.conf     'include' statement, or explicitly include this new     configuration file in /etc/ipsec.conf.

  - A FIPS self-test prevented libreswan from properly     starting in FIPS mode. This bug has been fixed and     libreswan now works in FIPS mode as expected.

In addition, this update adds the following enhancements :

  - A new option 'seedbits=' has been added to pre-seed the     Network Security Services (NSS) pseudo random number     generator (PRNG) function with entropy from the     /dev/random file on startup. This option is disabled by     default. It can be enabled by setting the 'seedbits='     option in the 'config setup' section in the     /etc/ipsec.conf file.

  - The build process now runs a Cryptographic Algorithm     Validation Program (CAVP) certification test on the     Internet Key Exchange version 1 and 2 (IKEv1 and IKEv2)     PRF/PRF+ functions.

Updated libreswan packages that fix one security issue, several bugs and add two enhancements are now available for Red Hat Enterprise Linux 7.

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

A flaw was discovered in the way Libreswan's IKE daemon processed certain IKEv1 payloads. A remote attacker could send specially crafted IKEv1 payloads that, when processed, would lead to a denial of service (daemon crash). (CVE-2015-3204)

Red Hat would like to thank Javantea for reporting this issue.

This update fixes the following bugs :

* Previously, the programs/pluto/state.h and programs/pluto/kernel_netlink.c files had a maximum SELinux context size of 257 and 1024 respectively. These restrictions set by libreswan limited the size of the context that can be exchanged by pluto (the IPSec daemon) when using a Labeled Internet Protocol Security (IPsec).
The SElinux labels for Labeled IPsec have been extended to 4096 bytes and the mentioned restrictions no longer exist. (BZ#1198650)

* On some architectures, the kernel AES_GCM IPsec algorithm did not work properly with acceleration drivers. On those kernels, some acceleration modules are added to the modprobe blacklist. However, Libreswan was ignoring this blacklist, leading to AES_GCM failures.
This update adds support for the module blacklist to the libreswan packages and thus prevents the AES_GCM failures from occurring.
(BZ#1208022)

* An IPv6 issue has been resolved that prevented ipv6-icmp Neighbour Discovery from working properly once an IPsec tunnel is established (and one endpoint reboots). When upgrading, ensure that /etc/ipsec.conf is loading all /etc/ipsec.d/*conf files using the /etc/ipsec.conf 'include' statement, or explicitly include this new configuration file in /etc/ipsec.conf. (BZ#1208023)

* A FIPS self-test prevented libreswan from properly starting in FIPS mode. This bug has been fixed and libreswan now works in FIPS mode as expected. (BZ#1211146)

In addition, this update adds the following enhancements :

* A new option 'seedbits=' has been added to pre-seed the Network Security Services (NSS) pseudo random number generator (PRNG) function with entropy from the /dev/random file on startup. This option is disabled by default. It can be enabled by setting the 'seedbits=' option in the 'config setup' section in the /etc/ipsec.conf file.
(BZ#1198649)

* The build process now runs a Cryptographic Algorithm Validation Program (CAVP) certification test on the Internet Key Exchange version 1 and 2 (IKEv1 and IKEv2) PRF/PRF+ functions. (BZ#1213652)

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

From Red Hat Security Advisory 2015:1154 :

Updated libreswan packages that fix one security issue, several bugs and add two enhancements are now available for Red Hat Enterprise Linux 7.

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

A flaw was discovered in the way Libreswan's IKE daemon processed certain IKEv1 payloads. A remote attacker could send specially crafted IKEv1 payloads that, when processed, would lead to a denial of service (daemon crash). (CVE-2015-3204)

Red Hat would like to thank Javantea for reporting this issue.

This update fixes the following bugs :

* Previously, the programs/pluto/state.h and programs/pluto/kernel_netlink.c files had a maximum SELinux context size of 257 and 1024 respectively. These restrictions set by libreswan limited the size of the context that can be exchanged by pluto (the IPSec daemon) when using a Labeled Internet Protocol Security (IPsec).
The SElinux labels for Labeled IPsec have been extended to 4096 bytes and the mentioned restrictions no longer exist. (BZ#1198650)

* On some architectures, the kernel AES_GCM IPsec algorithm did not work properly with acceleration drivers. On those kernels, some acceleration modules are added to the modprobe blacklist. However, Libreswan was ignoring this blacklist, leading to AES_GCM failures.
This update adds support for the module blacklist to the libreswan packages and thus prevents the AES_GCM failures from occurring.
(BZ#1208022)

* An IPv6 issue has been resolved that prevented ipv6-icmp Neighbour Discovery from working properly once an IPsec tunnel is established (and one endpoint reboots). When upgrading, ensure that /etc/ipsec.conf is loading all /etc/ipsec.d/*conf files using the /etc/ipsec.conf 'include' statement, or explicitly include this new configuration file in /etc/ipsec.conf. (BZ#1208023)

* A FIPS self-test prevented libreswan from properly starting in FIPS mode. This bug has been fixed and libreswan now works in FIPS mode as expected. (BZ#1211146)

In addition, this update adds the following enhancements :

* A new option 'seedbits=' has been added to pre-seed the Network Security Services (NSS) pseudo random number generator (PRNG) function with entropy from the /dev/random file on startup. This option is disabled by default. It can be enabled by setting the 'seedbits=' option in the 'config setup' section in the /etc/ipsec.conf file.
(BZ#1198649)

* The build process now runs a Cryptographic Algorithm Validation Program (CAVP) certification test on the Internet Key Exchange version 1 and 2 (IKEv1 and IKEv2) PRF/PRF+ functions. (BZ#1213652)

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

ID	Name	Product	Family	Severity
89906	GLSA-201603-13 : Libreswan: Multiple Vulnerabilities	Nessus	Gentoo Local Security Checks	medium
84393	Scientific Linux Security Update : libreswan on SL7.x x86_64 (20150623)	Nessus	Scientific Linux Local Security Checks	medium
84360	RHEL 7 : libreswan (RHSA-2015:1154)	Nessus	Red Hat Local Security Checks	medium
84354	Oracle Linux 7 : libreswan (ELSA-2015-1154)	Nessus	Oracle Linux Local Security Checks	medium
84348	CentOS 7 : libreswan (CESA-2015:1154)	Nessus	CentOS Local Security Checks	medium

Detections

Analytics

CVE-2015-3204

high

Tenable Plugins

medium

medium

medium

medium

medium