A vulnerability was discovered and corrected in bind: BIND 9 nameservers using the DNS64 IPv6 transition mechanism are vulnerable to a software defect that allows a crafted query to crash the server with a REQUIRE assertion failure. Remote exploitation of this defect can be achieved without extensive effort, resulting in a denial-of-service vector against affected servers . The updated packages have been upgraded to bind 9.8.4-P1 which is not vulnerable to this issue.