9.3 - RHSA-2016:2779

Problem Description:

An update for nss and nss-util is now available for Red Hat Enterprise Linux 5, Red Hat Enterprise Linux 6, and 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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux (v. 5 server) - i386, ia64, ppc, s390x, x86_64 Red Hat Enterprise Linux Client (v. 7) - x86_64 Red Hat Enterprise Linux Client Optional (v. 7) - x86_64 Red Hat Enterprise Linux ComputeNode (v. 7) - x86_64 Red Hat Enterprise Linux ComputeNode Optional (v. 7) - x86_64 Red Hat Enterprise Linux Desktop (v. 5 client) - i386, x86_64 Red Hat Enterprise Linux Desktop (v. 6) - i386, x86_64 Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64 Red Hat Enterprise Linux Desktop Workstation (v. 5 client) - i386, x86_64 Red Hat Enterprise Linux HPC Node (v. 6) - x86_64 Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64 Red Hat Enterprise Linux Server (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server (v. 7) - aarch64, ppc64, ppc64le, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 7) - aarch64, ppc64, ppc64le, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 6) - i386, x86_64 Red Hat Enterprise Linux Workstation (v. 7) - x86_64 Red Hat Enterprise Linux Workstation Optional (v. 6) - i386, x86_64 Red Hat Enterprise Linux Workstation Optional (v. 7) - x86_64

3. Description:

Network Security Services (NSS) is a set of libraries designed to support the cross-platform development of security-enabled client and server applications.

The nss-util packages provide utilities for use with the Network Security Services (NSS) libraries.

The following packages have been upgraded to a newer upstream version: nss (3.12.3), nss-util (3.12.3).

Security Fix(es):

* Multiple buffer handling flaws were found in the way NSS handled cryptographic data from the network. A remote attacker could use these flaws to crash an application using NSS or, possibly, execute arbitrary code with the permission of the user running the application. (CVE-2016-2834)

* A NULL pointer dereference flaw was found in the way NSS handled invalid Diffie-Hellman keys. A remote client could use this flaw to crash a TLS/SSL server using NSS. (CVE-2016-5285)

* It was found that Diffie Hellman Client key exchange handling in NSS was vulnerable to small subgroup confinement attack. An attacker could use this flaw to recover private keys by confining the client DH key to small subgroup of the desired group. (CVE-2016-8635)

Red Hat would like to thank the Mozilla project for reporting CVE-2016-2834. The CVE-2016-8635 issue was discovered by Hubert Kario (Red Hat). Upstream acknowledges Tyson Smith and Jed Davis as the original reporter of CVE-2016-2834.

4. Solution:

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

After installing this update, applications using NSS (for example, Firefox) must be restarted for this update to take effect.

5. Bugs fixed (https://bugzilla.redhat.com/):

1347908 - CVE-2016-2834 nss: Multiple security flaws (MFSA 2016-61) 1383883 - CVE-2016-5285 nss: Missing NULL check in PK11_SignWithSymKey / ssl3_ComputeRecordMACConstantTime causes server crash 1391818 - CVE-2016-8635 nss: small-subgroups attack flaw