RHSA-2016:0495 - Security Advisory

Topic

Updated nss-util packages that fix one security issue are now available for
Red Hat Enterprise Linux 6.2, 6.4, and 6.5 Advanced Update Support, and Red
Hat Enterprise Linux 6.6 and 7.1 Extended Update Support.

Red Hat Product Security has rated this update as having Critical 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.

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 package provides a set of utilities for NSS and
the Softoken module.

A heap-based buffer overflow flaw was found in the way NSS parsed certain
ASN.1 structures. An attacker could use this flaw to create a specially
crafted certificate which, when parsed by NSS, could cause it to crash, or
execute arbitrary code, using the permissions of the user running an
application compiled against the NSS library. (CVE-2016-1950)

Red Hat would like to thank the Mozilla project for reporting this issue.
Upstream acknowledges Francis Gabriel as the original reporter.

All nss-util users are advised to upgrade to these updated packages, which
contain a backported patch to correct this issue. For the update to take
effect, all applications linked to the nss and nss-util libraries must be
restarted, or the system rebooted.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

For details on how to apply this update, refer to:

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

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.1 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.6 i386
• Red Hat Enterprise Linux Server - AUS 6.6 x86_64
• Red Hat Enterprise Linux Server - AUS 6.5 x86_64
• Red Hat Enterprise Linux Server - AUS 6.4 x86_64
• Red Hat Enterprise Linux Server - AUS 6.2 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.1 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.6 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.1 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.6 ppc64
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.1 ppc64le
• Red Hat Enterprise Linux Server - TUS 6.6 x86_64
• Red Hat Enterprise Linux Server - TUS 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.6 i386
• Red Hat Enterprise Linux EUS Compute Node 7.1 x86_64
• Red Hat Enterprise Linux EUS Compute Node 6.6 x86_64

Fixes

• BZ - 1310509 - CVE-2016-1950 nss: Heap buffer overflow vulnerability in ASN1 certificate parsing (MFSA 2016-35)

CVEs

• CVE-2016-1950

References

• https://access.redhat.com/security/updates/classification/#critical
• https://www.mozilla.org/en-US/security/advisories/mfsa2016-36