## Release Notes for BIND Version 9.11.0-P5

### Introduction

This document summarizes changes since BIND 9.11.0:

BIND 9.11.0-P4 addresses the security issue described in CVE-2017-3136, and updates the built in trusted keys for the root zone.

BIND 9.11.0-P3 addresses the security issue described in CVE-2017-3135, and fixes a regression introduced in a prior security release.

BIND 9.11.0-P2 addresses the security issues described in CVE-2016-9131, CVE-2016-9147, CVE-2016-9444 and CVE-2016-9778.

BIND 9.11.0-P1 addresses the security issue described in CVE-2016-8864.

### Download

The latest versions of BIND 9 software can always be found at http://www.isc.org/downloads/. There you will find additional information about each release, source code, and pre-compiled versions for Microsoft Windows operating systems.

### New DNSSEC Root Key

ICANN is in the process of introducing a new Key Signing Key (KSK) for the global root zone. BIND has multiple methods for managing DNSSEC trust anchors, with somewhat different behaviors. If the root key is configured using the managed-keys statement, or if the pre-configured root key is enabled by using dnssec-validation auto, then BIND can keep keys up to date automatically. Servers configured in this way will roll seamlessly to the new key when it is published in the root zone. However, keys configured using the trusted-keys statement are not automatically maintained. If your server is performing DNSSEC validation and is configured using trusted-keys, you are advised to change your configuration before the root zone begins signing with the new KSK. This is currently scheduled for October 11, 2017.

This release includes an updated version of the `bind.keys` file containing the new root key. This file can also be downloaded from https://www.isc.org/bind-keys .

### Security Fixes

- Some chaining (i.e., type CNAME or DNAME) responses to upstream queries could trigger assertion failures. This flaw is disclosed in CVE-2017-3137. [RT #44734]

- dns64 with break-dnssec yes; can result in an assertion failure. This flaw is disclosed in CVE-2017-3136. [RT #44653]

- If a server is configured with a response policy zone (RPZ) that rewrites an answer with local data, and is also configured for DNS64 address mapping, a NULL pointer can be read triggering a server crash. This flaw is disclosed in CVE-2017-3135. [RT #44434]

- A coding error in the `nxdomain-redirect` feature could lead to an assertion failure if the redirection namespace was served from a local authoritative data source such as a local zone or a DLZ instead of via recursive lookup. This flaw is disclosed in CVE-2016-9778. [RT #43837]

- named could mishandle authority sections with missing RRSIGs, triggering an assertion failure. This flaw is disclosed in CVE-2016-9444. [RT #43632]

- named mishandled some responses where covering RRSIG records were returned without the requested data, resulting in an assertion failure. This flaw is disclosed in CVE-2016-9147. [RT #43548]

- named incorrectly tried to cache TKEY records which could trigger an assertion failure when there was a class mismatch. This flaw is disclosed in CVE-2016-9131. [RT #43522]

- It was possible to trigger assertions when processing responses containing answers of type DNAME. This flaw is disclosed in CVE-2016-8864. [RT #43465]

### New Features

- None.

### Feature Changes

- None.

### Porting Changes

- None.

### Bug Fixes

- A synthesized CNAME record appearing in a response before the associated DNAME could be cached, when it should not have been. This was a regression introduced while addressing CVE-2016-8864. [RT #44318]

### End of Life

The end of life for BIND 9.11 is yet to be determined but will not be before BIND 9.13.0 has been released for 6 months. https://www.isc.org/downloads/software-support-policy/

### Thank You

Thank you to everyone who assisted us in making this release possible. If you would like to contribute to ISC to assist us in continuing to make quality open source software, please visit our donations page at http://www.isc.org/donate/.