X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/efad2f414afac1b1456299e79b1cdc705b84b71e..de498d230862bcc49acbc6d5e76c71b1e15596c3:/doc/doc-txt/ChangeLog diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog index 62801740b..f858c9121 100644 --- a/doc/doc-txt/ChangeLog +++ b/doc/doc-txt/ChangeLog @@ -1,10 +1,226 @@ -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. +Since Exim version 4.94 +----------------------- + +JH/02 Bug 2587: Fix pam expansion condition. Tainted values are commonly used + as arguments, so an implementation trying to copy these into a local + buffer was taking a taint-enforcement trap. Fix by using dynamically + created buffers. + +JH/03 Bug 2586: Fix listcount expansion operator. Using tainted arguments is + reasonable, eg. to count headers. Fix by using dynamically created + buffers rather than a local, + + +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. + +JH/19 Bug 2507: Modules: on handling a dynamic-module (lookups) open failure, + only retrieve the errormessage once. Previously two calls to dlerror() + were used, and the second one (for mainlog/paniclog) retrieved null + information. + +JH/20 Taint checking: disallow use of tainted data for + - the appendfile transport file and directory options + - the pipe transport command + - the autoreply transport file, log and once options + - file names used by the redirect router (including filter files) + - named-queue names + - paths used by single-key lookups + Previously this was permitted. + +JH/21 Bug 2501: Fix init call in the heimdal authenticator. Previously it + adjusted the size of a major service buffer; this failed because the + buffer was in use at the time. Change to a compile-time increase in the + buffer size, when this authenticator is compiled into exim. + +JH/22 Taint-checking: move to safe-mode taint checking on all platforms. The + previous fast-mode was untenable in the face of glibs using mmap to + support larger malloc requests. + +PP/01 Update the openssl_options possible values through OpenSSL 1.1.1c. + New values supported, if defined on system where compiled: + allow_no_dhe_kex, cryptopro_tlsext_bug, enable_middlebox_compat, + no_anti_replay, no_encrypt_then_mac, prioritize_chacha, tlsext_padding + +JH/23 Performance improvement in the initial phase of a two-pass queue run. By + running a limited number of proceses in parallel, a benefit is gained. The + amount varies with the platform hardware and load. The use of the option + queue_run_in_order means we cannot do this, as ordering becomes + indeterminate. + +JH/24 Bug 2524: fix the cyrus_sasl auth driver gssapi usage. A previous fix + had introduced a string-copy (for ensuring NUL-termination) which was not + appropriate for that case, which can include embedded NUL bytes in the + block of data. Investigation showed the copy to actually be needless, the + data being length-specified. + +JH/25 Fix use of concurrent TLS connections under GnuTLS. When a callout was + done during a receiving connection, and both used TLS, global info was + used rather than per-connection info for tracking the state of data + queued for transmission. This could result in a connection hang. + +JH/26 Fix use of the SIZE parameter on MAIL commands, on continued connections. + Previously, when delivering serveral messages down a single connection + only the first would provide a SIZE. This was due to the size information + not being properly tracked. + +JH/27 Bug 2530: When operating in a timezone with sub-minute offset, such as + TAI (at 37 seconds currently), pretend to be in UTC for time-related + expansion and logging. Previously, spurious values such as a future + minute could be seen. + +JH/28 Bug 2533: Fix expansion of ${tr } item. When called in some situations + it could crash from a null-deref. This could also affect the + ${addresses: } operator and ${readsock } item. + +JH/29 Bug 2537: Fix $mime_part_count. When a single connection had a non-mime + message following a mime one, the variable was not reset. + +JH/30 When an pipelined-connect fails at the first response, assume incorrect + cached capability (perhaps the peer reneged?) and immediately retry in + non-pipelined mode. + +JH/31 Fix spurious detection of timeout while writing to transport filter. + +JH/32 Bug 2541: Fix segfault on bad cmdline -f (sender) argument. Previously + an attempt to copy the string was made before checking it. + +JH/33 Fix the dsearch lookup to return an untainted result. Previously the + taint of the lookup key was maintained; we now regard the presence in the + filesystem as sufficient validation. + +JH/34 Fix the readsocket expansion to not segfault when an empty "options" + argument is supplied. + +JH/35 The dsearch lookup now requires that the directory is an absolute path. + Previously this was not checked, and nonempty relative paths made an + access under Exim's current working directory. + +JH/36 Bug 2554: Fix msg:defer event for the hosts_max_try_hardlimit case. + Previously no event was raised. + +JH/37 Bug 2552: Fix the check on spool space during reception to use the SIZE + parameter supplied by the sender MAIL FROM command. Previously it was + ignored, and only the check_spool_space option value for the required + leeway checked. + +JH/38 Fix $dkim_key_length. This should, after a DKIM verification, present + the size of the signing public-key. Previously it was instead giving + the size of the signature hash. + +JH/39 DKIM verification: the RFC 8301 restriction on sizes of RSA keys is now + the default. See the (new) dkim_verify_min_keysizes option. + +JH/40 Fix a memory-handling bug: when a connection carried multiple messages + and an ACL use a lookup for checking either the local_part or domain, + stale data could be accessed. Ensure that variable references are + dropped between messages. + +JH/41 Bug 2571: Fix SPA authenticator. Running as a server, an offset supplied + by the client was not checked as pointing within response data before + being used. A malicious client could thus cause an out-of-bounds read and + possibly gain authentication. Fix by adding the check. + +JH/42 Internationalisation: change the default for downconversion in the smtp + transport to be "if needed". Previously it was "as previously set" for + the message, which usually meant "if needed" for message-submission but + "no" for everything else. However, MTAs have been seen using SMTPUTF8 + even when the envelope addresses did not need it, resulting in forwarding + failures to non-supporting MTAs. A downconvert in such cases will be + a no-op on the addresses, merely dropping the use of SMTPUTF8 by the + transport. The change does mean that addresses needing conversion will + be converted when previously a delivery failure would occur. + +JH/43 Fix possible long line in DSN. Previously when a very long SMTP error + response was received it would be used unchecked in a fail-DSN, violating + standards on line-length limits. Truncate if needed. + +HS/01 Remove parameters of the link to www.open-spf.org. The linked form + doesn't work. (Additionally add a new main config option to configure the + spf_smtp_comment) + + Exim version 4.93 ----------------- @@ -70,10 +286,10 @@ HS/01 Bug 2390: Use message_id for tempfile creation to avoid races in a systems which restrict the file name length to lower values. (It was "hdr.$pid".) -HS/01 Bug 2390: Use message_id for tempfile creation to avoid races in a +HS/02 Bug 2390: Use message_id for tempfile creation to avoid races in a shared (NFS) environment. -HS/02 Bug 2392: exigrep does case sensitive *option* processing (as it +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. @@ -121,9 +337,108 @@ 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 platfor supports and has the facility enabled, it will + 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 -----------------