glibc - security update

Several vulnerabilities have been fixed in the GNU C Library, glibc.

The first vulnerability listed below is considered to have critical
impact.

• CVE-2015-7547
  The Google Security Team and Red Hat discovered that the glibc
  host name resolver function, getaddrinfo, when processing
  AF_UNSPEC queries (for dual A/AAAA lookups), could mismanage its
  internal buffers, leading to a stack-based buffer overflow and
  arbitrary code execution. This vulnerability affects most
  applications which perform host name resolution using getaddrinfo,
  including system services.
• CVE-2015-8776
  Adam Nielsen discovered that if an invalid separated time value
  is passed to strftime, the strftime function could crash or leak
  information. Applications normally pass only valid time
  information to strftime; no affected applications are known.
• CVE-2015-8778
  Szabolcs Nagy reported that the rarely-used hcreate and hcreate_r
  functions did not check the size argument properly, leading to a
  crash (denial of service) for certain arguments. No impacted
  applications are known at this time.
• CVE-2015-8779
  The catopen function contains several unbound stack allocations
  (stack overflows), causing it the crash the process (denial of
  service). No applications where this issue has a security impact
  are currently known.

While it is only necessary to ensure that all processes are not using
the old glibc anymore, it is recommended to reboot the machines after
applying the security upgrade.

For the stable distribution (jessie), these problems have been fixed in
version 2.19-18+deb8u3.

For the unstable distribution (sid), these problems will be fixed in
version 2.21-8.

We recommend that you upgrade your glibc packages.