6.8 - RHSA-2016:0225

Problem Description:

Updated glibc 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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux ComputeNode EUS (v. 7.1) - x86_64 Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.1) - x86_64 Red Hat Enterprise Linux HPC Node EUS (v. 6.6) - x86_64 Red Hat Enterprise Linux HPC Node Optional EUS (v. 6.6) - x86_64 Red Hat Enterprise Linux Server AUS (v. 6.2) - x86_64 Red Hat Enterprise Linux Server AUS (v. 6.4) - x86_64 Red Hat Enterprise Linux Server AUS (v. 6.5) - x86_64 Red Hat Enterprise Linux Server EUS (v. 6.6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server EUS (v. 7.1) - ppc64, ppc64le, s390x, x86_64 Red Hat Enterprise Linux Server Optional AUS (v. 6.2) - x86_64 Red Hat Enterprise Linux Server Optional AUS (v. 6.4) - x86_64 Red Hat Enterprise Linux Server Optional AUS (v. 6.5) - x86_64 Red Hat Enterprise Linux Server Optional EUS (v. 6.6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional EUS (v. 7.1) - ppc64, ppc64le, s390x, x86_64

3. Description:

The glibc packages provide the standard C libraries (libc), POSIX thread libraries (libpthread), standard math libraries (libm), and the Name Server Caching Daemon (nscd) used by multiple programs on the system. Without these libraries, the Linux system cannot function correctly.

A stack-based buffer overflow was found in the way the libresolv library performed dual A/AAAA DNS queries. A remote attacker could create a specially crafted DNS response which could cause libresolv to crash or, potentially, execute code with the permissions of the user running the library. Note: this issue is only exposed when libresolv is called from the nss_dns NSS service module. (CVE-2015-7547)

This issue was discovered by the Google Security Team and Red Hat.

All glibc users are advised to upgrade to these updated packages, which contain a backported patch to correct this issue.

4. 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

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

1293532 - CVE-2015-7547 glibc: getaddrinfo stack-based buffer overflow