Critical CentOS glibc Security Update


glibc-2.12-1.166.el6_7.7.i686.rpm, glibc-2.12-1.166.el6_7.7.src.rpm, glibc-2.12-1.166.el6_7.7.x86_64.rpm, glibc-common-2.12-1.166.el6_7.7.i686.rpm, glibc-common-2.12-1.166.el6_7.7.x86_64.rpm, glibc-devel-2.12-1.166.el6_7.7.i686.rpm, glibc-devel-2.12-1.166.el6_7.7.x86_64.rpm, glibc-headers-2.12-1.166.el6_7.7.i686.rpm, glibc-headers-2.12-1.166.el6_7.7.x86_64.rpm, glibc-static-2.12-1.166.el6_7.7.i686.rpm, glibc-static-2.12-1.166.el6_7.7.x86_64.rpm, glibc-utils-2.12-1.166.el6_7.7.i686.rpm, glibc-utils-2.12-1.166.el6_7.7.x86_64.rpm, nscd-2.12-1.166.el6_7.7.i686.rpm, nscd-2.12-1.166.el6_7.7.x86_64.rpm,
2018-01-18 11:11
2017-07-27 19:10
2017-04-01 19:09
2017-01-05 20:13


Updated glibc packages that fix one security issue and two bugs are now
available for Red Hat Enterprise Linux 6.

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.

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.

This update also fixes the following bugs:

* The dynamic loader has been enhanced to allow the loading of more shared
libraries that make use of static thread local storage. While static thread
local storage is the fastest access mechanism it may also prevent the
shared library from being loaded at all since the static storage space is a
limited and shared process-global resource. Applications which would
previously fail with "dlopen: cannot load any more object with static TLS"
should now start up correctly. (BZ#1291270)

* A bug in the POSIX realtime support would cause asynchronous I/O or
certain timer API calls to fail and return errors in the presence of large
thread-local storage data that exceeded PTHREAD_STACK_MIN in size
(generally 16 KiB). The bug in librt has been corrected and the impacted
APIs no longer return errors when large thread-local storage data is
present in the application. (BZ#1301625)

All glibc users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues.
Please see

Am I vulnerable?

The constraints below list the versions that this vulnerability is patched in, and versions that are unaffected. If a patch is ready but unrealeased, then it is pending.

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Affected package information

Release Package Patched in
6 glibc glibc-2.12-1.166.el6_7.7.i686.rpm
glibc glibc-2.12-1.166.el6_7.7.src.rpm
glibc glibc-2.12-1.166.el6_7.7.x86_64.rpm
glibc-common glibc-common-2.12-1.166.el6_7.7.i686.rpm
glibc-common glibc-common-2.12-1.166.el6_7.7.x86_64.rpm
glibc-devel glibc-devel-2.12-1.166.el6_7.7.i686.rpm
glibc-devel glibc-devel-2.12-1.166.el6_7.7.x86_64.rpm
glibc-headers glibc-headers-2.12-1.166.el6_7.7.i686.rpm
glibc-headers glibc-headers-2.12-1.166.el6_7.7.x86_64.rpm
glibc-static glibc-static-2.12-1.166.el6_7.7.i686.rpm
glibc-static glibc-static-2.12-1.166.el6_7.7.x86_64.rpm
glibc-utils glibc-utils-2.12-1.166.el6_7.7.i686.rpm
glibc-utils glibc-utils-2.12-1.166.el6_7.7.x86_64.rpm
nscd nscd-2.12-1.166.el6_7.7.i686.rpm
nscd nscd-2.12-1.166.el6_7.7.x86_64.rpm