Security update for ntp (important)

ntp was updated to version 4.2.8p6 to fix 12 security issues.

Also yast2-ntp-client was updated to match some sntp syntax changes.
(bsc#937837)

These security issues were fixed:

• CVE-2015-8158: Fixed potential infinite loop in ntpq (bsc#962966).
• CVE-2015-8138: Zero Origin Timestamp Bypass (bsc#963002).
• CVE-2015-7979: Off-path Denial of Service (DoS) attack on authenticated
  broadcast mode (bsc#962784).
• CVE-2015-7978: Stack exhaustion in recursive traversal of restriction
  list (bsc#963000).
• CVE-2015-7977: reslist NULL pointer dereference (bsc#962970).
• CVE-2015-7976: ntpq saveconfig command allows dangerous characters in
  filenames (bsc#962802).
• CVE-2015-7975: nextvar() missing length check (bsc#962988).
• CVE-2015-7974: Skeleton Key: Missing key check allows impersonation
  between authenticated peers (bsc#962960).
• CVE-2015-7973: Replay attack on authenticated broadcast mode
  (bsc#962995).
• CVE-2015-8140: ntpq vulnerable to replay attacks (bsc#962994).
• CVE-2015-8139: Origin Leak: ntpq and ntpdc, disclose origin (bsc#962997).
• CVE-2015-5300: MITM attacker could have forced ntpd to make a step
  larger than the panic threshold (bsc#951629).

These non-security issues were fixed:

• fate#320758 bsc#975981: Enable compile-time support for MS-SNTP
  (–enable-ntp-signd). This replaces the w32 patches in 4.2.4 that added
  the authreg directive.
• bsc#962318: Call /usr/sbin/sntp with full path to synchronize in
  start-ntpd. When run as cron job, /usr/sbin/ is not in the path, which
  caused the synchronization to fail.
• bsc#782060: Speedup ntpq.
• bsc#916617: Add /var/db/ntp-kod.
• bsc#956773: Add ntp-ENOBUFS.patch to limit a warning that might happen
  quite a lot on loaded systems.
• bsc#951559,bsc#975496: Fix the TZ offset output of sntp during DST.
• Add ntp-fork.patch and build with threads disabled to allow name
  resolution even when running chrooted.