This update for bind fixes the following issues:
CVE-2017-3137 (bsc#1033467): Mistaken assumptions about the ordering of records in the answer section of a response containing CNAME or DNAME resource records could have been exploited to cause a denial of service of a bind server performing recursion.
CVE-2017-3136 (bsc#1033466): An attacker could have constructed a query that would cause a denial of service of servers configured to use DNS64.
CVE-2017-3138 (bsc#1033468): An attacker with access to the BIND control channel could have caused the server to stop by triggering an assertion failure.
CVE-2016-6170 (bsc#987866): Primary DNS servers could have caused a denial of service of secondary DNS servers via a large AXFR response. IXFR servers could have caused a denial of service of IXFR clients via a large IXFR response. Remote authenticated users could have caused a denial of service of primary DNS servers via a large UPDATE message.
CVE-2016-2775 (bsc#989528): When lwresd or the named lwres option were enabled, bind allowed remote attackers to cause a denial of service (daemon crash) via a long request that uses the lightweight resolver protocol.
One additional non-security bug was fixed:
The default umask was changed to 077. (bsc#1020983)