This update for bind fixes the following issues:
An attacker with the ability to send and receive messages to an authoritative DNS server was able to circumvent TSIG authentication of AXFR requests. A server that relied solely on TSIG keys for protection could be manipulated into (1) providing an AXFR of a zone to an unauthorized recipient and (2) accepting bogus Notify packets. [bsc#1046554, CVE-2017-3142]
An attacker who with the ability to send and receive messages to an authoritative DNS server and who had knowledge of a valid TSIG key name for the zone and service being targeted was able to manipulate BIND into accepting an unauthorized dynamic update. [bsc#1046555, CVE-2017-3143]