X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/ddd16464764026559f8efe414ca6ac05406618a4..549d36ddec8c419af2223cc83162f58e9106650f:/doc/doc-txt/ChangeLog diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog index 9fc466365..ce225e949 100644 --- a/doc/doc-txt/ChangeLog +++ b/doc/doc-txt/ChangeLog @@ -1,10 +1,498 @@ -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 - 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 +----------------- + +JH/01 Remove code calling the customisable local_scan function, unless a new + definition "HAVE_LOCAL_SCAN=yes" is present in the Local/Makefile. + +JH/02 Bug 1007: Avoid doing logging from signal-handlers, as that can result in + non-signal-safe functions being used. + +JH/03 Bug 2269: When presented with a received message having a stupidly large + number of DKIM-Signature headers, disable DKIM verification to avoid + a resource-consumption attack. The limit is set at twenty. + +JH/04 Add variables $arc_domains, $arc_oldest_pass for ARC verify. Fix the + report of oldest_pass in ${authres } in consequence, and separate out + some descriptions of reasons for verification fail. + +JH/05 Bug 2273: Cutthrough delivery left a window where the received messsage + files in the spool were present and unlocked. A queue-runner could spot + them, resulting in a duplicate delivery. Fix that by doing the unlock + after the unlink. Investigation by Tim Stewart. Take the opportunity to + add more error-checking on spoolfile handling while that code is being + messed with. + +PP/01 Refuse to open a spool data file (*-D) if it's a symlink. + No known attacks, no CVE, this is defensive hardening. + +JH/06 Bug 2275: The MIME ACL unlocked the received message files early, and + a queue-runner could start a delivery while other operations were ongoing. + Cutthrough delivery was a common victim, resulting in duplicate delivery. + Found and investigated by Tim Stewart. Fix by using the open message data + file handle rather than opening another, and not locally closing it (which + releases a lock) for that case, while creating the temporary .eml format + file for the MIME ACL. Also applies to "regex" and "spam" ACL conditions. + +JH/07 Bug 177: Make a random-recipient callout success visible in ACL, by setting + $sender_verify_failure/$recipient_verify_failure to "random". + +JH/08 When generating a selfsigned cert, use serial number 1 since zero is not + legitimate. + +JH/09 Bug 2274: Fix logging of cmdline args when starting in an unlinked cwd. + Previously this would segfault. + +JH/10 Fix ARC signing for case when DKIM signing failed. Previously this would + segfault. + +JH/11 Bug 2264: Exim now only follows CNAME chains one step by default. We'd + like zero, since the resolver should be doing this for us, But we need one + as a CNAME but no MX presence gets the CNAME returned; we need to check + that doesn't point to an MX to declare it "no MX returned" rather than + "error, loop". A new main option is added so the older capability of + following some limited number of chain links is maintained. + +JH/12 Add client-ip info to non-pass iprev ${authres } lines. + +JH/13 For receent Openssl versions (1.1 onward) use modern generic protocol + methods. These should support TLS 1.3; they arrived with TLS 1.3 and the + now-deprecated earlier definitions used only specified the range up to TLS + 1.2 (in the older-version library docs). + +JH/14 Bug 2284: Fix DKIM signing for body lines starting with a pair of dots. + +JH/15 Rework TLS client-side context management. Stop using a global, and + explicitly pass a context around. This enables future use of TLS for + connections to service-daemons (eg. malware scanning) while a client smtp + connection is using TLS; with cutthrough connections this is quite likely. + +JH/16 Fix ARC verification to do AS checks in reverse order. + +JH/17 Support a "tls" option on the ${readsocket } expansion item. + +JH/18 Bug 2287: Fix the protocol name (eg utf8esmtp) for multiple messages + using the SMTPUTF8 option on their MAIL FROM commands, in one connection. + Previously the "utf8" would be re-prepended for every additional message. + +JH/19 Reject MAIL FROM commands with SMTPUTF8 when the facility was not advertised. + Previously thery were accepted, resulting in issues when attempting to + forward messages to a non-supporting MTA. + +PP/02 Let -n work with printing macros too, not just options. + +JH/20 Bug 2296: Fix cutthrough for >1 address redirection. Previously only + one parent address was copied, and bogus data was used at delivery-logging + time. Either a crash (after delivery) or bogus log data could result. + Discovery and analysis by Tim Stewart. + +PP/03 Make ${utf8clean:} expansion operator detect incomplete final character. + Previously if the string ended mid-character, we did not insert the + promised '?' replacement. + +PP/04 Documentation: current string operators work on bytes, not codepoints. + +JH/21 Change as many as possible of the global flags into one-bit bitfields; these + should pack well giving a smaller memory footprint so better caching and + therefore performance. Group the declarations where this can't be done so + that the byte-sized flag variables are not interspersed among pointer + variables, giving a better chance of good packing by the compiler. + +JH/22 Bug 1896: Fix the envelope from for DMARC forensic reports to be possibly + non-null, to avoid issues with sites running BATV. Previously reports were + sent with an empty envelope sender so looked like bounces. + +JH/23 Bug 2318: Fix the noerror command within filters. It wasn't working. + The ignore_error flag wasn't being returned from the filter subprocess so + was not set for later routers. Investigation and fix by Matthias Kurz. + +JH/24 Bug 2310: Raise a msg:fail:internal event for each undelivered recipient, + and a msg:complete for the whole, when a message is manually removed using + -Mrm. Developement by Matthias Kurz, hacked on by JH. + +JH/25 Avoid fixed-size buffers for pathnames in DB access. This required using + a "Gnu special" function, asprintf() in the DB utility binary builds; I + hope that is portable enough. + +JH/26 Bug 2311: Fix DANE-TA verification under GnuTLS. Previously it was also + requiring a known-CA anchor certificate; make it now rely entirely on the + TLSA as an anchor. Checking the name on the leaf cert against the name + on the A-record for the host is still done for TA (but not for EE mode). + +JH/27 Fix logging of proxy address. Previously, a pointless "PRX=[]:0" would be + included in delivery lines for non-proxied connections, when compiled with + SUPPORT_SOCKS and running with proxy logging enabled. + +JH/28 Bug 2314: Fire msg:fail:delivery event even when error is being ignored. + Developement by Matthias Kurz, tweaked by JH. While in that bit of code, + move the existing event to fire before the normal logging of message + failure so that custom logging is bracketed by normal logging. + +JH/29 Bug 2322: A "fail" command in a non-system filter (file) now fires the + msg:fail:internal event. Developement by Matthias Kurz. + +JH/30 Bug 2329: Increase buffer size used for dns lookup from 2k, which was + far too small for todays use of crypto signatures stored there. Go all + the way to the max DNS message size of 64kB, even though this might be + overmuch for IOT constrained device use. + +JH/31 Fix a bad use of a copy function, which could be used to pointlessly + copy a string over itself. The library routine is documented as not + supporting overlapping copies, and on MacOS it actually raised a SIGABRT. + +JH/32 For main options check_spool_space and check_inode_space, where the + platform supports 64b integers, support more than the previous 2^31 kB + (i.e. more than 2 TB). Accept E, P and T multipliers in addition to + the previous G, M, k. + +JH/33 Bug 2338: Fix the cyrus-sasl authenticator to fill in the + $authenticated_fail_id variable on authentication failure. Previously + it was unset. + +JH/34 Increase RSA keysize of autogen selfsign cert from 1024 to 2048. RHEL 8.0 + OpenSSL didn't want to use such a weak key. Do for GnuTLS also, and for + more-modern GnuTLS move from GNUTLS_SEC_PARAM_LOW to + GNUTLS_SEC_PARAM_MEDIUM. + +JH/35 OpenSSL: fail the handshake when SNI processing hits a problem, server + side. Previously we would continue as if no SNI had been received. + +JH/36 Harden the handling of string-lists. When a list consisted of a sole + "<" character, which should be a list-separator specification, we walked + off past the nul-terimation. + +JH/37 Bug 2341: Send "message delayed" warning MDNs (restricted to external + causes) even when the retry time is not yet met. Previously they were + not, meaning that when (say) an account was over-quota and temp-rejecting, + and multiple senders' messages were queued, only one sender would get + notified on each configured delay_warning cycle. + +JH/38 Bug 2351: Log failures to extract envelope addresses from message headers. + +JH/39 OpenSSL: clear the error stack after an SSL_accept(). With anon-auth + cipher-suites, an error can be left on the stack even for a succeeding + accept; this results in impossible error messages when a later operation + actually does fail. + +AM/01 Bug 2359: GnuTLS: repeat lowlevel read and write operations while they + return error codes indicating retry. Under TLS1.3 this becomes required. + +JH/40 Fix the feature-cache refresh for EXPERIMENTAL_PIPE_CONNECT. Previously + 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 ----------------- @@ -206,6 +694,15 @@ JH/37 Bug 2255: Revert the disable of the OpenSSL session caching. This PP/03 Add util/renew-opendmarc-tlds.sh script for safe renewal of public suffix list. +JH/38 DKIM: accept Ed25519 pubkeys in SubjectPublicKeyInfo-wrapped form, + since the IETF WG has not yet settled on that versus the original + "bare" representation. + +JH/39 Fix syslog logging for syslog_timestamp=no and log_selector +millisec. + Previously the millisecond value corrupted the output. + Fix also for syslog_pid=no and log_selector +pid, for which the pid + corrupted the output. + Exim version 4.90 ----------------- @@ -362,7 +859,7 @@ JH/26 Fix DKIM bug: when the pseudoheader generated for signing was exactly line, the header hash was calculated to an incorrect value thanks to the (relaxed) space the fold became. -HS/02 Fix Bug 2130: large writes from the transport subprocess where chunked +HS/02 Fix Bug 2130: large writes from the transport subprocess were chunked and confused the parent. JH/27 Fix SOCKS bug: an unitialized pointer was deref'd by the transport process