(RHSA-2013:0769) Low: glibc security and bug fix update

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.

It was found that getaddrinfo() did not limit the amount of stack memory
used during name resolution. An attacker able to make an application
resolve an attacker-controlled hostname or IP address could possibly cause
the application to exhaust all stack memory and crash. (CVE-2013-1914)

A flaw was found in the regular expression matching routines that process
multibyte character input. If an application utilized the glibc regular
expression matching mechanism, an attacker could provide specially-crafted
input that, when processed, would cause the application to crash.
(CVE-2013-0242)

This update also fixes the following bugs:

• The improvements RHSA-2012:1207 made to the accuracy of floating point
  functions in the math library caused performance regressions for those
  functions. The performance regressions were analyzed and a fix was applied
  that retains the current accuracy but reduces the performance penalty to
  acceptable levels. Refer to Red Hat Knowledge solution 229993, linked
  to in the References, for further information. (BZ#950535)

• It was possible that a memory location freed by the localization code
  could be accessed immediately after, resulting in a crash. The fix ensures
  that the application does not crash by avoiding the invalid memory access.
  (BZ#951493)

Users of glibc are advised to upgrade to these updated packages, which
contain backported patches to correct these issues.