The remote DNS server may be affected by multiple attack vectors.
Versions of ISC BIND 9.x prior to 9.8.5, and 9.9.x prior to 9.9.3 are unpatched for a flaw that is triggered when handling a packet with a malformed options section. This may allow a remote attacker to trigger an assertion failure and cause a server to exit.
Upgrade ISC BIND to version 9.9.3 or later. If version 9.9.x cannot be obtained, version 9.8.5 is also patched for this vulnerability.