Analysis of ISC BIND DNAME Answer Handling DoS (CVE-2016-8864)

A defect in BIND's handling of a DNAME answer was fixed in a critical update from the Internet Systems Consortium (ISC) several days ago. This defect affects all BIND recursive servers, and can be exploited to remotely take down recursive servers by sending a simple DNAME answer thereby causing a denial of service (DoS.) This potential DoS vulnerability is caused by an assertion failure in Resolver.c or Db.c when caching the DNS response with DNAME Record. In this post we will examine the underlying code and expose the root cause of this...

Leave a Reply