This indicates an attack attempt to exploit a Denial of Service vulnerability in ISC BIND.
The vulnerability is due to an improper bound checking when the vulnerable application handles a crafted DNSKEY record. A remote attacker may be able to exploit this to cause a denial of service condition on the affected system.
ISC BIND 9.9.7 up to 9.9.7-P2
ISC BIND 9.10.2 up to 9.10.2-P3
Denial of Service: Remote attackers can crash vulnerable systems or services
Apply the most recent upgrade or patch from the vendor.