--- /dev/null
+.. Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+..
+.. SPDX-License-Identifier: MPL-2.0
+..
+.. This Source Code Form is subject to the terms of the Mozilla Public
+.. License, v. 2.0. If a copy of the MPL was not distributed with this
+.. file, you can obtain one at https://mozilla.org/MPL/2.0/.
+..
+.. See the COPYRIGHT file distributed with this work for additional
+.. information regarding copyright ownership.
+
+Notes for BIND 9.20.5
+---------------------
+
+Security Fixes
+~~~~~~~~~~~~~~
+
+- [CVE-2024-12705] DNS-over-HTTP(s) flooding fixes.
+
+ Fix DNS-over-HTTP(S) implementation issues that arise under heavy
+ query load. Optimize resource usage for :iscman:`named` instances that
+ accept queries over DNS-over-HTTP(S).
+
+ Previously, :iscman:`named` would process all incoming HTTP/2 data at
+ once, which could overwhelm the server, especially when dealing with
+ clients that send requests but don't wait for responses. That has been
+ fixed. Now, :iscman:`named` handles HTTP/2 data in smaller chunks and
+ throttles reading until the remote side reads the response data. It
+ also throttles clients that send too many requests at once.
+
+ Additionally, :iscman:`named` now carefully processes data sent by
+ some clients, which can be considered "flooding." It logs these
+ clients and drops connections from them. :gl:`#4795`
+
+ In some cases, :iscman:`named` could leave DNS-over-HTTP(S)
+ connections in the `CLOSE_WAIT` state indefinitely. That also has been
+ fixed. ISC would like to thank JF Billaud for thoroughly investigating
+ the issue and verifying the fix. :gl:`#5083` :gl:`#4795` :gl:`#5083`
+
+- [CVE-2024-11187] Limit the additional processing for large RDATA sets.
+
+ When answering queries, don't add data to the additional section if
+ the answer has more than 13 names in the RDATA. This limits the number
+ of lookups into the database(s) during a single client query, reducing
+ query processing load. :gl:`#5034`
+
+New Features
+~~~~~~~~~~~~
+
+- Add Extended DNS Error Code 22 - No Reachable Authority.
+
+ When the resolver is trying to query an authority server and
+ eventually timed out, a SERVFAIL answer is given to the client. Add
+ the Extended DNS Error Code 22 - No Reachable Authority to the
+ response. :gl:`#2268`
+
+- Add a new option to configure the maximum number of outgoing queries
+ per client request.
+
+ The configuration option 'max-query-count' sets how many outgoing
+ queries per client request is allowed. The existing
+ 'max-recursion-queries' is the number of permissible queries for a
+ single name and is reset on every CNAME redirection. This new option
+ is a global limit on the client request. The default is 200.
+
+ This allows us to send a bit more queries while looking up a single
+ name. The default for 'max-recursion-queries' is changed from 32 to
+ 50. :gl:`#4980` :gl:`#4921`
+
+Feature Changes
+~~~~~~~~~~~~~~~
+
+- The configuration clauses parental-agents and primaries are renamed to
+ remote-servers.
+
+ The top blocks 'primaries' and 'parental-agents' are no longer
+ preferred and should be renamed to 'remote-servers'. The zone
+ statements 'parental-agents' and 'primaries' are still used, and may
+ refer to any 'remote-servers' top block. :gl:`#4544`
+
+- Add none parameter to query-source and query-source-v6 to disable IPv4
+ or IPv6 upstream queries.
+
+ Add a none parameter to named configuration option `query-source`
+ (respectively `query-source-v6`) which forbid usage of IPv4
+ (respectively IPv6) addresses when named is doing an upstream query.
+ :gl:`#4981` Turning-off upstream IPv6 queries while still listening to
+ downstream queries on IPv6.
+
+- Revert "Fix NSEC3 closest encloser lookup for names with empty
+ non-terminals"
+
+ Revert the fix for #4950 for 9.20.
+
+ This reverts MR !9438.
+
+ History: A performance improvement for NSEC3 closest encloser lookups
+ (#4460) was introduced (in MR !9436) and backported to 9.20 (MR !9438)
+ and to 9.18 in (MR !9439). It was released in 9.18.30 (and 9.20.2 and
+ 9.21.1).
+
+ There was a bug in the code (#4950), so we reverted the change in
+ !9611, !9613 and !9614 (not released).
+
+ Then a new attempt was merged in main (MR !9610) and backported to
+ 9.20 (MR !9631) and 9.18 (MR !9632). The latter should not have been
+ backported and was reverted in !9689.
+
+ We now also revert the fix for 9.20 :gl:`#5108`
+
+Bug Fixes
+~~~~~~~~~
+
+- Fix nsupdate hang when processing a large update.
+
+ To mitigate DNS flood attacks over a single TCP connection, we
+ throttle the connection when the other side does not read the data.
+ Throttling should only occur on server-side sockets, but erroneously
+ also happened for nsupdate, which acts as a client. When nsupdate
+ started throttling the connection, it never attempts to read again.
+ This has been fixed. :gl:`#4910`
+
+- Fix possible assertion failure when reloading server while processing
+ updates.
+
+ :gl:`#5006`
+
+- Preserve cache across reconfig when using attach-cache.
+
+ When the `attach-cache` option is used in the `options` block with an
+ arbitrary name, it causes all views to use the same cache. Previously,
+ this configuration caused the cache to be deleted and a new cache
+ created every time the server was reconfigured. This has been fixed.
+ :gl:`#5061`
+
+- Resolve the spurious drops in performance due GLUE cache.
+
+ For performance reasons, the returned GLUE records are cached on the
+ first use. The current implementation could randomly cause a
+ performance drop and increased memory use. This has been fixed.
+ :gl:`#5064`
+
+- Fix dnssec-signzone signing non-DNSKEY RRsets with revoked keys.
+
+ `dnssec-signzone` was using revoked keys for signing RRsets other than
+ DNSKEY. This has been corrected. :gl:`#5070`
+
+- Unknown directive in resolv.conf not handled properly.
+
+ The line after an unknown directive in resolv.conf could accidentally
+ be skipped, potentially affecting dig, host, nslookup, nsupdate, or
+ delv. This has been fixed. :gl:`#5084`
+
+- Fix response policy zones and catalog zones with an $INCLUDE statement
+ defined.
+
+ Response policy zones (RPZ) and catalog zones were not working
+ correctly if they had an $INCLUDE statement defined. This has been
+ fixed. :gl:`#5111`
+
+
projects / thirdparty / bind9.git / commitdiff
