-Change log file for Exim from version 4.21
-------------------------------------------
This document describes *changes* to previous versions, that might
affect Exim's operation, with an unchanged configuration file. For new
options, and new features, see the NewStuff file next to this ChangeLog.
+Exim version 4.94
+-----------------
+
+JH/01 Avoid costly startup code when not strictly needed. This reduces time
+ for some exim process initialisations. It does mean that the logging
+ of TLS configuration problems is only done for the daemon startup.
+
+JH/02 Early-pipelining support code is now included unless disabled in Makefile.
+
+JH/03 DKIM verification defaults no long accept sha1 hashes, to conform to
+ RFC 8301. They can still be enabled, using the dkim_verify_hashes main
+ option.
+
+JH/04 Support CHUNKING from an smtp transport using a transport_filter, when
+ DKIM signing is being done. Previously a transport_filter would always
+ disable CHUNKING, falling back to traditional DATA.
+
+JH/05 Regard command-line receipients as tainted.
+
+JH/06 Bug 340: Remove the daemon pid file on exit, whe due to SIGTERM.
+
+JH/07 Bug 2489: Fix crash in the "pam" expansion condition. It seems that the
+ PAM library frees one of the arguments given to it, despite the
+ documentation. Therefore a plain malloc must be used.
+
+JH/08 Bug 2491: Use tainted buffers for the transport smtp context. Previously
+ on-stack buffers were used, resulting in a taint trap when DSN information
+ copied from a received message was written into the buffer.
+
+JH/09 Bug 2493: Harden ARC verify against Outlook, whick has been seen to mix
+ the ordering of its ARC headers. This caused a crash.
+
+JH/10 Bug 2492: Use tainted memory for retry record when needed. Previously when
+ a new record was being constructed with information from the peer, a trap
+ was taken.
+
+JH/11 Bug 2494: Unset the default for dmarc_tld_file. Previously a naiive
+ installation would get error messages from DMARC verify, when it hit the
+ nonexistent file indicated by the default. Distros wanting DMARC enabled
+ should both provide the file and set the option.
+ Also enforce no DMARC verification for command-line sourced messages.
+
+JH/12 Fix an uninitialised flag in early-pipelining. Previously connections
+ could, depending on the platform, hang at the STARTTLS response.
+
+JH/13 Bug 2498: Reset a counter used for ARC verify before handling another
+ message on a connection. Previously if one message had ARC headers and
+ the following one did not, a crash could result when adding an
+ Authentication-Results: header.
+
+JH/14 Bug 2500: Rewind some of the common-coding in string handling between the
+ Exim main code and Exim-related utities. The introduction of taint
+ tracking also did many adjustments to string handling. Since then, eximon
+ frequently terminated with an assert failure.
+
+JH/15 When PIPELINING, synch after every hundred or so RCPT commands sent and
+ check for 452 responses. This slightly helps the inefficieny of doing
+ a large alias-expansion into a recipient-limited target. The max_rcpt
+ transport option still applies (and at the current default, will override
+ the new feature). The check is done for either cause of synch, and forces
+ a fast-retry of all 452'd recipients using a new MAIL FROM on the same
+ connection. The new facility is not tunable at this time.
+
+JH/16 Fix the variables set by the gsasl authenticator. Previously a pointer to
+ library live data was being used, so the results became garbage. Make
+ copies while it is still usable.
+
+JH/17 Logging: when the deliver_time selector ise set, include the DT= field
+ on delivery deferred (==) and failed (**) lines (if a delivery was
+ attemtped). Previously it was only on completion (=>) lines.
+
+JH/18 Authentication: the gsasl driver not provides the $authN variables in time
+ for the expansion of the server_scram_iter and server_scram_salt options.
+
+WB/01 SPF: DNS lookups for the obsolete SPF RR type done by the libspf2 library
+ are now specifically given a NO_DATA response without hitting the system
+ resolver. The library goes on to do the now-standard TXT lookup.
+ Use of dnsdb lookups is not affected.
+
+
+
+Exim version 4.93
+-----------------
+
+JH/01 OpenSSL: With debug enabled output keying information sufficient, server
+ side, to decode a TLS 1.3 packet capture.
+
+JH/02 OpenSSL: Suppress the sending of (stateful) TLS1.3 session tickets.
+ Previously the default library behaviour applied, sending two, each in
+ its own TCP segment.
+
+JH/03 Debug output for ACL now gives the config file name and line number for
+ each verb.
+
+JH/04 The default received_header_text now uses the RFC 8314 tls cipher clause.
+
+JH/05 DKIM: ensure that dkim_domain elements are lowercased before use.
+
+JH/06 Fix buggy handling of autoreply bounce_return_size_limit, and a possible
+ buffer overrun for (non-chunking) other transports.
+
+JH/07 GnuTLS: Our use of late (post-handshake) certificate verification, under
+ TLS1.3, means that a server rejecting a client certificate is not visible
+ to the client until the first read of encrypted data (typically the
+ response to EHLO). Add detection for that case and treat it as a failed
+ TLS connection attempt, so that the normal retry-in-clear can work (if
+ suitably configured).
+
+JB/01 Bug 2375: fix expansions of 822 addresses having comments in local-part
+ and/or domain. Found and fixed by Jason Betts.
+
+JH/08 Add hardening against SRV & TLSA lookups the hit CNAMEs (a nonvalid
+ configuration). If a CNAME target was not a wellformed name pattern, a
+ crash could result.
+
+JH/09 Logging: Fix initial listening-on line for multiple ports for an IP when
+ the OS reports them interleaved with other addresses.
+
+JH/10 OpenSSL: Fix aggregation of messages. Previously, when PIPELINING was
+ used both for input and for a verify callout, both encrypted, SMTP
+ responses being sent by the server could be lost. This resulted in
+ dropped connections and sometimes bounces generated by a peer sending
+ to this system.
+
+JH/11 Harden plaintext authenticator against a badly misconfigured client-send
+ string. Previously it was possible to cause undefined behaviour in a
+ library routine (usually a crash). Found by "zerons".
+
+JH/12 Bug 2384: fix "-bP smtp_receive_timeout". Previously it returned no
+ output.
+
+JH/13 Bug 2386: Fix builds with Dane under LibreSSL 2.9.0 onward. Some old
+ API was removed, so update to use the newer ones.
+
+JH/14 Bug 1891: Close the log file if receiving a non-smtp message, without
+ any timeout set, is taking a long time. Previously we would hang on to a
+ rotated logfile "forever" if the input was arriving with long gaps
+ (a previous attempt to fix addressed lack, for a long time, of initial
+ input).
+
+HS/01 Bug 2390: Use message_id for tempfile creation to avoid races in a
+ shared (NFS) environment. The length of the tempfile name is now
+ 4 + 16 ("hdr.$message_exim_id") which might break on file
+ systems which restrict the file name length to lower values.
+ (It was "hdr.$pid".)
+
+HS/02 Bug 2390: Use message_id for tempfile creation to avoid races in a
+ shared (NFS) environment.
+
+HS/03 Bug 2392: exigrep does case sensitive *option* processing (as it
+ did for all versions <4.90). Notably -M, -m, --invert, -I may be
+ affected.
+
+JH/15 Use unsigned when creating bitmasks in macros, to avoid build errors
+ on some platforms for bit 31.
+
+JH/16 GnuTLS: rework ciphersuite strings under recent library versions. Thanks
+ to changes apparently associated with TLS1.3 handling some of the APIs
+ previously used were either nonfunctional or inappropriate. Strings
+ like TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM__AEAD:256
+ and TLS1.2:ECDHE_SECP256R1__RSA_SHA256__AES_128_CBC__SHA256:128 replace
+ the previous TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256 .
+ This affects log line X= elements, the $tls_{in,out}_cipher variables,
+ and the use of specific cipher names in the encrypted= ACL condition.
+
+JH/17 OpenSSL: the default openssl_options now disables ssl_v3.
+
+JH/18 GnuTLS: fix $tls_out_ocsp under hosts_request_ocsp. Previously the
+ verification result was not updated unless hosts_require_ocsp applied.
+
+JH/19 Bug 2398: fix listing of a named-queue. Previously, even with the option
+ queue_list_requires_admin set to false, non-admin users were denied the
+ facility.
+
+JH/20 Bug 2389: fix server advertising of usable certificates, under GnuTLS in
+ directory-of-certs mode. Previously they were advertised despite the
+ documentation.
+
+JH/21 The smtp transport option "hosts_noproxy_tls" is now unset by default.
+ A single TCP connection by a client will now hold a TLS connection open
+ for multiple message deliveries, by default. Previoud the default was to
+ not do so.
+
+JH/22 The smtp transport option "hosts_try_dane" now enables all hosts by
+ default. If built with the facility, DANE will be used. The facility
+ SUPPORT_DANE is now enabled in the prototype build Makefile "EDITME".
+
+JH/23 The build default is now for TLS to be included; the SUPPORT_TLS define
+ is replaced with DISABLE_TLS. Either USE_GNUTLS or (the new) USE_OPENSSL
+ must be defined and you must still, unless you define DISABLE_TLS, manage
+ the the include-dir and library-file requirements that go with that
+ choice. Non-TLS builds are still supported.
+
+JH/24 Fix duplicated logging of peer name/address, on a transport connection-
+ reject under TFO.
+
+JH/25 The smtp transport option "hosts_try_fastopen" now enables all hosts by
+ default. If the platform supports and has the facility enabled, it will
+ be requested on all coneections.
+
+JH/26 The PIPE_CONNECT facility is promoted from experimental status and is now
+ controlled by the build-time option SUPPORT_PIPE_CONNECT.
+
+PP/01 Unbreak heimdal_gssapi, broken in 4.92.
+
+JH/27 Bug 2404: Use the main-section configuration option "dsn_from" for
+ success-DSN messages. Previously the From: header was always the default
+ one for these; the option was ignored.
+
+JH/28 Fix the timeout on smtp response to apply to the whole response.
+ Previously it was reset for every read, so a teergrubing peer sending
+ single bytes within the time limit could extend the connection for a
+ long time. Credit to Qualsys Security Advisory Team for the discovery.
+
+JH/29 Fix DSN Final-Recipient: field. Previously it was the post-routing
+ delivery address, which leaked information of the results of local
+ forwarding. Change to the original envelope recipient address, per
+ standards.
+
+JH/30 Bug 2411: Fix DSN generation when RFC 3461 failure notification is
+ requested. Previously not bounce was generated and a log entry of
+ error ignored was made.
+
+JH/31 Avoid re-expansion in ${sort } expansion. (CVE-2019-13917)
+
+JH/32 Introduce a general tainting mechanism for values read from the input
+ channel, and values derived from them. Refuse to expand any tainted
+ values, to catch one form of exploit.
+
+JH/33 Bug 2413: Fix dkim_strict option. Previously the expansion result
+ was unused and the unexpanded text used for the test. Found and
+ fixed by Ruben Jenster.
+
+JH/34 Fix crash after TLS shutdown. When the TCP/SMTP channel was left open,
+ an attempt to use a TLS library read routine dereffed a nul pointer,
+ causing a segfault.
+
+JH/35 Bug 2409: filter out-of-spec chars from callout response before using
+ them in our smtp response.
+
+JH/36 Have the general router option retry_use_local_part default to true when
+ any of the restrictive preconditions are set (to anything). Previously it
+ was only for check_local user. The change removes one item of manual
+ configuration which is required for proper retries when a remote router
+ handles a subset of addresses for a domain.
+
+JH/37 Appendfile: when evaluating quota use (non-quota_size_regex) take the file
+ link count into consideration.
+
+HS/04 Fix handling of very log lines in -H files. If a -<key> <value> line
+ caused the extension of big_buffer, the following lines were ignored.
+
+JH/38 Bug 1395: Teach the DNS negative-cache about TTL value from the SOA in
+ accordance with RFC 2308. Previously there was no expiry, so a longlived
+ receive process (eg. due to ACL delays) versus a short SOA value could
+ surprise.
+
+HS/05 Handle trailing backslash gracefully. (CVE-2019-15846)
+
+JH/39 Promote DMARC support to mainline.
+
+JH/40 Bug 2452: Add a References: header to DSNs.
+
+JH/41 With GnuTLS 3.6.0 (and later) do not attempt to manage Diffie-Hellman
+ parameters. The relevant library call is documented as "Deprecated: This
+ function is unnecessary and discouraged on GnuTLS 3.6.0 or later. Since
+ 3.6.0, DH parameters are negotiated following RFC7919."
+
+HS/06 Change the default of dnssec_request_domains to "*"
+
+JH/42 Bug 2545: Fix CHUNKING for all RCPT commands rejected. Previously we
+ carried on and emitted a BDAT command, even when PIPELINING was not
+ active.
+
+JH/43 Bug 2465: Fix taint-handling in dsearch lookup. Previously a nontainted
+ buffer was used for the filename, resulting in a trap when tainted
+ arguments (eg. $domain) were used.
+
+JH/44 With OpenSSL 1.1.1 (onwards) disable renegotiation for TLS1.2 and below;
+ recommended to avoid a possible server-load attack. The feature can be
+ re-enabled via the openssl_options main cofiguration option.
+
+JH/45 local_scan API: documented the current smtp_printf() call. This changed
+ for version 4.90 - adding a "more data" boolean to the arguments.
+ Bumped the ABI version number also, this having been missed previously;
+ release versions 4.90 to 4.92.3 inclusive were effectively broken in
+ respect of usage of smtp_printf() by either local_scan code or libraries
+ accessed via the ${dlfunc } expansion item. Both will need coding
+ adjustment for any calls to smtp_printf() to match the new function
+ signature; a FALSE value for the new argument is always safe.
+
+JH/46 FreeBSD: fix use of the sendfile() syscall. The shim was not updating
+ the file-offset (which the Linux syscall does, and exim expects); this
+ resulted in an indefinite loop.
+
+JH/47 ARC: fix crash in signing, triggered when a configuration error failed
+ to do ARC verification. The Authentication-Results: header line added
+ by the configuration then had no ARC item.
+
+
Exim version 4.92
-----------------
it only wrote the new authenticators, resulting in a lack of tracking of
peer changes of ESMTP extensions until the next cache flush.
+JH/41 Fix the loop reading a message header line to check for integer overflow,
+ and more-often against header_maxsize. Previously a crafted message could
+ induce a crash of the recive process; now the message is cleanly rejected.
+
+JH/42 Bug 2366: Fix the behaviour of the dkim_verify_signers option. It had
+ been totally disabled for all of 4.91. Discovery and fix by "Mad Alex".
+
Exim version 4.91
-----------------
git://git.exim.org / users / jgh / exim.git / blobdiff