- Update to release 9.18.11
Security Fixes:
* An UPDATE message flood could cause named to exhaust all
available memory. This flaw was addressed by adding a new
update-quota option that controls the maximum number of
outstanding DNS UPDATE messages that named can hold in a queue
at any given time (default: 100). (CVE-2022-3094)
* named could crash with an assertion failure when an RRSIG query
was received and stale-answer-client-timeout was set to a
non-zero value. This has been fixed. (CVE-2022-3736)
* named running as a resolver with the
stale-answer-client-timeout option set to any value greater
than 0 could crash with an assertion failure, when the
recursive-clients soft quota was reached. This has been fixed.
(CVE-2022-3924)
New Features:
* The new update-quota option can be used to control the number
of simultaneous DNS UPDATE messages that can be processed to
update an authoritative zone on a primary server, or forwarded
to the primary server by a secondary server. The default is
100. A new statistics counter has also been added to record
events when this quota is exceeded, and the version numbers for
the XML and JSON statistics schemas have been updated.
Removed Features:
* The Differentiated Services Code Point (DSCP) feature in BIND
has been non-operational since the new Network Manager was
introduced in BIND 9.16. It is now marked as obsolete, and
vestigial code implementing it has been removed. Configuring
DSCP values in named.conf now causes a warning to be logged.
Feature Changes:
* The catalog zone implementation has been optimized to work with
hundreds of thousands of member zones.
Bug Fixes:
* A rare assertion failure was fixed in outgoing TCP DNS
connection handling.
* Large zone transfers over TLS (XoT) could fail. This has been
fixed.
* In addition to a previously fixed bug, another similar issue
was discovered where quotas could be erroneously reached for
servers, including any configured forwarders, resulting in
SERVFAIL answers being sent to clients. This has been fixed.
* In certain query resolution scenarios (e.g. when following
CNAME records), named configured to answer from stale cache
could return a SERVFAIL response despite a usable, non-stale
answer being present in the cache. This has been fixed.
* When an outgoing request timed out, named would retry up to
three times with the same server instead of trying the next
available name server. This has been fixed.
* Recently used ADB names and ADB entries (IP addresses) could
get cleaned when ADB was under memory pressure. To mitigate
this, only actual ADB names and ADB entries are now counted
(excluding internal memory structures used for “housekeeping”)
and recently used (<= 10 seconds) ADB names and entries are
excluded from the overmem memory cleaner.
* The “Prohibited” Extended DNS Error was inadvertently set in
some NOERROR responses. This has been fixed.
* Previously, TLS session resumption could have led to handshake
failures when client certificates were used for authentication
(Mutual TLS). This has been fixed.
[bsc#1207471, bsc#1207473, bsc#1207475]