﻿id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc
13680	bind bind9 9.16.4	Douglas R. Reno	Bruce Dubbs	"New security release

ISC has posted the announcement below to our public ""bind-announce"" list, 
completing the disclosure of two medium-severity vulnerabilities, 
CVE-2020-8618 and CVE-2020-8619.

Package maintainers and distributors who have been holding updated 
packages in anticipation of our disclosure are free to proceed 
now that this information has been made public.

Thank you to all those who received the information in advance for your 
cooperation with our embargo period.

Michael McNally - ISC Security Officer

ISC's June maintenance releases of BIND are available and can be downloaded
from the ISC software download page, https://www.isc.org/download

A summary of changes in the new releases can be found in their release notes:

current supported stable branches:

- 9.11.20 - 
  https://downloads.isc.org/isc/bind9/9.11.20/RELEASE-NOTES-bind-9.11.20.html
- 9.16.4  - 
  https://downloads.isc.org/isc/bind9/9.16.4/RELEASE-NOTES-bind-9.16.4.html


experimental development branch:

- 9.17.2 - 
  https://downloads.isc.org/isc/bind9/9.17.2/RELEASE-NOTES-bind-9.17.2.html

In addition to minor bug fixes and feature improvements, these particular
maintenance releases of BIND also contain fixes for two medium-severity
vulnerabilities, CVE-2020-8618 and CVE-2020-8619, about which more information is available in these Security Advisories:

- https://kb.isc.org/docs/cve-2020-8618
- https://kb.isc.org/docs/cve-2020-8619


The release notes: Notes for BIND 9.16.4

Security Fixes

It was possible to trigger an assertion when attempting to fill an oversized
TCP buffer. This was disclosed in CVE-2020-8618. 
    
It was possible to trigger an INSIST failure when a zone with an interior wildcard label was queried in a certain pattern. This was disclosed in CVE-2020-8619. 

New Features

Documentation was converted from DocBook to reStructuredText. The BIND 9 ARM is now generated using Sphinx and published on Read the Docs. Release notes are no longer available as a separate document accompanying a release.

named and named-checkzone now reject master zones that have a DS RRset at the 
zone apex. Attempts to add DS records at the zone apex via UPDATE will be 
logged but otherwise ignored. DS records belong in the parent zone, not 
at the zone apex.

dig and other tools can now print the Extended DNS Error (EDE) 
option when it appears in a request or a response. 

Feature Changes

The default value of max-stale-ttl has changed from 1 week to 12 hours. 
This option controls how long named retains expired RRsets in cache as a
potential mitigation mechanism, should there be a problem with one or more
domains. Note that cache content retention is independent of whether stale 
answers are used in response to client queries (stale-answer-enable yes|no and 
rndc serve-stale on|off). Serving of stale answers when the authoritative 
servers are not responding must be explicitly enabled, whereas the retention 
of expired cache content takes place automatically on all versions of BIND 9 
that have this feature available.

    Warning

This change may be significant for administrators who expect that 
stale cache content will be automatically retained for up to 1 week. 
Add option max-stale-ttl 1w; to named.conf to keep the previous 
behavior of named.

listen-on-v6 { any; } creates a separate socket for each interface. 
Previously, just one socket was created on systems conforming to RFC 3493 and 
RFC 3542. This change was introduced in BIND 9.16.0, but it was accidentally 
omitted from documentation. 

Bug Fixes

When fully updating the NSEC3 chain for a large zone via IXFR, a temporary 
loss of performance could be experienced on the secondary server when 
answering queries for nonexistent data that required DNSSEC proof of non-
existence (in other words, queries that required the server to find and to 
return NSEC3 data). The unnecessary processing step that was causing this 
delay has now been removed.

named could crash with an assertion failure if the name of a 
database node was looked up while the database was being modified.

A possible deadlock in lib/isc/unix/socket.c was fixed.

Previously, named did not destroy some mutexes and conditional variables in
netmgr code, which caused a memory leak on FreeBSD. This has been fixed. 

A data race in lib/dns/resolver.c:log_formerr() that could lead to an 
assertion failure was fixed. 
    
Previously, provide-ixfr no; failed to return up-to-date responses when the serial
number was greater than or equal to the current serial number.

A bug in dnssec-policy keymgr was fixed, where the check for the existence of a 
given key’s successor would incorrectly return true if any other key in the 
keyring had a successor. 

With dnssec-policy, when creating a successor key, the “goal” state of the 
current active key (the predecessor) was not changed and thus never removed 
from the zone.

named-checkconf -p could include spurious text in server-addresses 
statements due to an uninitialized DSCP value. This has been fixed. 

The ARM has been updated to indicate that the TSIG session key is generated 
when named starts, regardless of whether it is needed.

"	enhancement	closed	high	10.0	BOOK	SVN	medium	fixed		
