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 4.97
+-----------------
+
+JH/01 The hosts_connection_nolog main option now also controls "no MAIL in
+ SMTP connection" log lines.
+
+JH/02 Option default value updates:
+ - queue_fast_ramp (main) true (was false)
+ - remote_max_parallel (main) 4 (was 2)
+
+JH/03 Cache static regex pattern compilations, for use by ACLs.
+
+JH/04 Bug 2903: avoid exit on an attempt to rewrite a malformed address.
+ Make the rewrite never match and keep the logging. Trust the
+ admin to be using verify=header-syntax (to actually reject the message).
+
+JH/05 Follow symlinks for placing a watch on TLS creds files. This means
+ (under Linux) we watch the dir containing the final file; previously
+ it would be the dir with the first symlink. We still do not monitor
+ the entire path.
+
+JH/06 Check for bad chars in rDNS for sender_host_name. The OpenBSD (at least)
+ dn_expand() is happy to pass them through.
+
+JH/07 OpenSSL Fix auto-reload of changed server OCSP proof. Previously, if
+ the file with the proof had an unchanged name, the new proof(s) were
+ loaded on top of the old ones (and nover used; the old ones were stapled).
+
+JH/08 Bug 2915: Fix use-after-free for $regex<n> variables. Previously when
+ more than one message arrived in a single connection a reference from
+ the earlier message could be re-used. Often a sigsegv resulted.
+ These variables were introduced in Exim 4.87.
+ Debug help from Graeme Fowler.
+
+JH/09 Fix ${filter } for conditions that modify $value. Previously the
+ modified version would be used in construction the result, and a memory
+ error would occur.
+
+JH/10 GnuTLS: fix for (IOT?) clients offering no TLS extensions at all.
+ Find and fix by Jasen Betts.
+
+JH/11 OpenSSL: fix for ancient clients needing TLS support for versions earlier
+ than TLSv1,2, Previously, more-recent versions of OpenSSL were permitting
+ the systemwide configuration to override the Exim config.
+
+HS/01 Bug 2728: Introduce EDITME option "DMARC_API" to work around incompatible
+ API changes in libopendmarc.
+
+JH/12 Bug 2930: Fix daemon startup. When started from any process apart from
+ pid 1, in the normal "background daemon" mode, having to drop process-
+ group leadership also lost track of needing to create listener sockets.
+
+JH/13 Bug 2929: Fix using $recipients after ${run...}. A change made for 4.96
+ resulted in the variable appearing empty. Find and fix by Ruben Jenster.
+
+JH/14 Bug 2933: Fix regex substring match variables for null matches. Since 4.96
+ a capture group which obtained no text (eg. "(abc)*" matching zero
+ occurrences) could cause a segfault if the corresponding $<n> was
+ expanded.
+
+JH/15 Fix argument parsing for ${run } expansion. Previously, when an argument
+ included a close-brace character (eg. it itself used an expansion) an
+ error occurred.
+
+JH/16 Move running the smtp connect ACL to before, for TLS-on-connect ports,
+ starting TLS. Previously it was after, meaning that attackers on such
+ ports had to be screened using the host_reject_connection main config
+ option. The new sequence aligns better with the STARTTLS behaviour, and
+ permits defences against crypto-processing load attacks, even though it
+ is strictly an incompatible change.
+ Also, avoid sending any SMTP fail response for either the connect ACL
+ or host_reject_connection, for TLS-on-connect ports.
+
+JH/17 Permit the ACL "encrypted" condition to be used in a HELO/EHLO ACL,
+ Previously this was not permitted, but it makes reasonable sense.
+ While there, restore a restriction on using it from a connect ACL; given
+ the change JH/16 it could only return false (and before 4.91 was not
+ permitted).
+
+JH/18 Fix a fencepost error in logging. Previously (since 4.92) when a log line
+ was exactly sized compared to the log buffer, a crash occurred with the
+ misleading message "bad memory reference; pool not found".
+ Found and traced by Jasen Betts.
+
+JH/19 Bug 2911: Fix a recursion in DNS lookups. Previously, if the main option
+ dns_again_means_nonexist included an element causing a DNS lookup which
+ iteslf returned DNS_AGAIN, unbounded recursion occurred. Possible results
+ included (though probably not limited to) a process crash from stack
+ memory limit, or from excessive open files. Replace this with a paniclog
+ whine (as this is likely a configuration error), and returning
+ DNS_NOMATCH.
+
+JH/20 Bug 2954: (OpenSSL) Fix setting of explicit EC curve/group. Previously
+ this always failed, probably leading to the usual downgrade to in-clear
+ connections.
+
+JH/21 Fix TLSA lookups. Previously dns_again_means_nonexist would affect
+ SERVFAIL results, which breaks the downgrade resistance of DANE. Change
+ to not checking that list for these lookups.
+
+JH/22 Bug 2434: Add connection-elapsed "D=" element to more connection
+ closure log lines.
+
+JH/23 Fix crash in string expansions. Previously, if an empty variable was
+ immediately followed by an expansion operator, a null-indirection read
+ was done, killing the process.
+
+JH/24 Bug 2997: When built with EXPERIMENTAL_DSN_INFO, bounce messages can
+ include an SMTP response string which is longer than that supported
+ by the delivering transport. Alleviate by wrapping such lines before
+ column 80.
+
+JH/25 Bug 2827: Restrict size of References: header in bounce messages to 998
+ chars (RFC limit). Previously a limit of 12 items was made, which with
+ a not-impossible References: in the message being bounced could still
+ be over-large and get stopped in the transport.
+
+JH/26 For a ${readsocket } in TLS mode, send a TLS Close Alert before the TCP
+ close. Previously a bare socket close was done.
+
+JH/27 Fix ${srs_encode ..}. Previously it would give a bad result for one day
+ every 1024 days.
+
+JH/28 Bug 2996: Fix a crash in the smtp transport. When finding that the
+ message being considered for delivery was already being handled by
+ another process, and having an SMTP connection already open, the function
+ to close it tried to use an uninitialized variable. This would afftect
+ high-volume sites more, especially when running mailing-list-style loads.
+ Pollution of logs was the major effect, as the other process delivered
+ the message. Found and partly investigated by Graeme Fowler.
+
+JH/29 Change format of the internal ID used for message identification. The old
+ version only supported 31 bits for a PID element; the new 64 (on systems
+ which can use Base-62 encoding, which is all currently supported ones
+ but not Darwin (MacOS) or Cygwin, which have case-insensitive filesystems
+ and must use Base-36). The new ID is 23 characters rather than 16, and is
+ visible in various places - notably logs, message headers, and spool file
+ names. Various of the ancillary utilities also have to know the format.
+ As well as the expanded PID portion, the sub-second part of the time
+ recorded in the ID is expanded to support finer precision. Theoretically
+ this permits a receive rate from a single comms channel of better than the
+ previous 2000/sec.
+ The major timestamp part of the ID is not changed; at 6 characters it is
+ usable until about year 3700.
+ Updating from previously releases is fully supported: old-format spool
+ files are still usable, and the utilities support both formats. New
+ message will use the new format. The one hints-DB file type which uses
+ message-IDs (the transport wait- DB) will be discarded if an old-format ID
+ is seen; new ones will be built with only new-format IDs.
+ Optionally, a utility can be used to convert spool files from old to new,
+ but this is only an efficiency measure not a requirement for operation
+ Downgrading from new to old requires running a provided utility, having
+ first stopped all operations. This will convert any spool files from new
+ back to old (losing time-precision and PID information) and remove any
+ wait- hints databases.
+
+JH/30 Bug 3006: Fix handling of JSON strings having embedded commas. Previously
+ we treated them as item separators when parsing for a list item, but they
+ need to be protected by the doublequotes. While there, add handling for
+ backslashes.
+
+JH/31 Bug 2998: Fix ${utf8clean:...} to disallow UTF-16 surrogate codepoints.
+ Found and fixed by Jasen Betts. No testcase for this as my usual text
+ editor insists on emitting only valid UTF-8.
+
+JH/32 Fix "tls_dhparam = none" under GnuTLS. At least with 3.7.9 this gave
+ a null-indirection SIGSEGV for the receive process.
+
+JH/33 Fix free for live variable $value created by a ${run ...} expansion during
+ -bh use. Internal checking would spot this and take a panic.
+
+JH/34 Bug 3013: Fix use of $recipients within arguments for ${run...}.
+ In 4.96 this would expand to empty.
+
+JH/35 Bug 3014: GnuTLS: fix expiry date for an auto-generated server
+ certificate. Find and fix by Andreas Metzler.
+
+JH/36 Add ARC info to DMARC hostory records.
+
+JH/37 Bug 3016: Avoid sending DSN when message was accepted under fakereject
+ or fakedefer. Previously the sender could discover that the message
+ had in fact been accepted.
+
+JH/38 Taint-track intermediate values from the peer in multi-stage authentation
+ sequences. Previously the input was not noted as being tainted; notably
+ this resulted in behaviour of LOGIN vs. PLAIN being inconsistent under
+ bad coding of authenticators.
+
+JH/39 Bug 3023: Fix crash induced by some combinations of zero-length strings
+ and ${tr...}. Found and diagnosed by Heiko Schlichting.
+
+
+Exim version 4.96
+-----------------
+
+JH/01 Move the wait-for-next-tick (needed for unique message IDs) from
+ after reception to before a subsequent reception. This should
+ mean slightly faster delivery, and also confirmation of reception
+ to senders.
+
+JH/02 Move from using the pcre library to pcre2. The former is no longer
+ being developed or supported (by the original developer).
+
+JH/03 Constification work in the filters module required a major version
+ bump for the local-scan API. Specifically, the "headers_charset"
+ global which is visible via the API is now const and may therefore
+ not be modified by local-scan code.
+
+JH/04 Fix ClamAV TCP use under FreeBSD. Previously the OS-specific shim for
+ sendfile() didi not account for the way the ClamAV driver code called it.
+
+JH/05 Bug 2819: speed up command-line messages being read in. Previously a
+ time check was being done for every character; replace that with one
+ per buffer.
+
+JH/06 Bug 2815: Fix ALPN sent by server under OpenSSL. Previously the string
+ sent was prefixed with a length byte.
+
+JH/07 Change the SMTP feature name for pipelining connect to be compliant with
+ RFC 5321. Previously Dovecot (at least) would log errors during
+ submission.
+
+JH/08 Remove stripping of the binaries from the FreeBSD build. This was added
+ in 4.61 without a reason logged. Binaries will be bigger, which might
+ matter on diskspace-constrained systems, but debug is easier.
+
+JH/09 Fix macro-definition during "-be" expansion testing. The move to
+ write-protected store for macros had not accounted for these runtime
+ additions; fix by removing this protection for "-be" mode.
+
+JH/10 Convert all uses of select() to poll(). FreeBSD 12.2 was found to be
+ handing out large-numbered file descriptors, violating the usual Unix
+ assumption (and required by Posix) that the lowest possible number will be
+ allocated by the kernel when a new one is needed. In the daemon, and any
+ child procesees, values higher than 1024 (being bigger than FD_SETSIZE)
+ are not useable for FD_SET() [and hence select()] and overwrite the stack.
+ Assorted crashes happen.
+
+JH/11 Fix use of $sender_host_name in daemon process. When used in certain
+ main-section options or in a connect ACL, the value from the first ever
+ connection was never replaced for subsequent connections. Found by
+ Wakko Warner.
+
+JH/12 Bug 2838: Fix for i32lp64 hard-align platforms. Found for SPARC Linux,
+ though only once PCRE2 was introduced: the memory accounting used under
+ debug offset allocations by an int, giving a hard trap in early startup.
+ Change to using a size_t. Debug and fix by John Paul Adrian Glaubitz.
+
+JH/13 Bug 2845: Fix handling of tls_require_ciphers for OpenSSL when a value
+ with underbars is given. The write-protection of configuration introduced
+ in 4.95 trapped when normalisation was applied to an option not needing
+ expansion action.
+
+JH/14 Bug 1895: TLS: Deprecate RFC 5114 Diffie-Hellman parameters.
+
+JH/15 Fix a resource leak in *BSD. An off-by-one error resulted in the daemon
+ failing to close the certificates directory, every hour or any time it
+ was touched.
+
+JH/16 Debugging initiated by an ACL control now continues through into routing
+ and transport processes. Previously debugging stopped any time Exim
+ re-execs, or for processing a queued message.
+
+JH/17 The "expand" debug selector now gives more detail, specifically on the
+ result of expansion operators and items.
+
+JH/18 Bug 2751: Fix include_directory in redirect routers. Previously a
+ bad comparison between the option value and the name of the file to
+ be included was done, and a mismatch was wrongly identified.
+ 4.88 to 4.95 are affected.
+
+JH/19 Support for Berkeley DB versions 1 and 2 is withdrawn.
+
+JH/20 When built with NDBM for hints DB's check for nonexistence of a name
+ supplied as the db file-pair basename. Previously, if a directory
+ path was given, for example via the autoreply "once" option, the DB
+ file.pag and file.dir files would be created in that directory's
+ parent.
+
+JH/21 Remove the "allow_insecure_tainted_data" main config option and the
+ "taint" log_selector. These were previously deprecated.
+
+JH/22 Fix static address-list lookups to properly return the matched item.
+ Previously only the domain part was returned.
+
+JH/23 Bug 2864: FreeBSD: fix transport hang after 4xx/5xx response. Previously
+ the call into OpenSSL to send a TLS Close was being repeated; this
+ resulted in the library waiting for the peer's Close. If that was never
+ sent we waited forever. Fix by tracking send calls.
+
+JH/24 The ${run} expansion item now expands its command string elements after
+ splitting. Previously it was before; the new ordering makes handling
+ zero-length arguments simpler. The old ordering can be obtained by
+ appending a new option "preexpand", after a comma, to the "run".
+
+JH/25 Taint-check exec arguments for transport-initiated external processes.
+ Previously, tainted values could be used. This affects "pipe", "lmtp" and
+ "queryprogram" transport, transport-filter, and ETRN commands.
+ The ${run} expansion is also affected: in "preexpand" mode no part of
+ the command line may be tainted, in default mode the executable name
+ may not be tainted.
+
+JH/26 Fix CHUNKING on a continued-transport. Previously the usabliility of
+ the the facility was not passed across execs, and only the first message
+ passed over a connection could use BDAT; any further ones using DATA.
+
+JH/27 Support the PIPECONNECT facility in the smtp transport when the helo_data
+ uses $sending_ip_address and an interface is specified.
+ Previously any use of the local address in the EHLO name disabled
+ PIPECONNECT, the common case being to use the rDNS of it.
+
+JH/28 OpenSSL: fix transport-required OCSP stapling verification under session
+ resumption. Previously verify failed because no certificate status is
+ passed on the wire for the restarted session. Fix by using the recorded
+ ocsp status of the stored session for the new connection.
+
+JH/29 TLS resumption: the key for session lookup in the client now includes
+ more info that a server could potentially use in configuring a TLS
+ session, avoiding oferring mismatching sessions to such a server.
+ Previously only the server IP was used.
+
+JH/30 Fix string_copyn() for limit greater than actual string length.
+ Previously the copied amount was the limit, which could result in a
+ overlapping memcpy for newly allocated destination soon after a
+ source string shorter than the limit. Found/investigated by KM.
+
+JH/31 Bug 2886: GnuTLS: Do not free the cached creds on transport connection
+ close; it may be needed for a subsequent connection. This caused a
+ SEGV on primary-MX defer. Found/investigated by Gedalya & Andreas.
+
+JH/32 Fix CHUNKING for a second message on a connection when the first was
+ rejected. Previously we did not reset the chunking-offered state, and
+ erroneously rejected the BDAT command. Investigation help from
+ Jesse Hathaway.
+
+JH/33 Fis ${srs_encode ...} to handle an empty sender address, now returning
+ an empty address. Previously the expansion returned an error.
+
+HS/01 Bug 2855: Handle a v4mapped sender address given us by a frontending
+ proxy. Previously these were misparsed, leading to paniclog entries.
+
Exim version 4.95
-----------------
JH/07 Bug 2597: Fix a resource leak. Using a lookup in obtaining a value for
smtp_accept_max_per_host allocated resources which were not released
when the limit was exceeded. This eventually crashed the daemon. Fix
- by adding a relase action in that path.
+ by adding a release action in that path.
JH/08 Bug 2598: Fix verify ACL condition. The options for the condition are
expanded; previously using tainted values was rejected. Fix by using
JH/16 Bug 2615: Fix pause during message reception, on systems that have been
suspended/resumed. The Linux CLOCK_MONOTONIC does not account for time
- spent suspended, ignoring the Posix definition. Previously we assumed
+ spent suspended, ignoring the POSIX definition. Previously we assumed
it did and a constant offset from real time could be used as a correction.
Change to using the same clock source for the start-of-message and the
post-message next-tick-wait. Also change to using CLOCK_BOOTTIME if it
JH/17 Bug 2295: Fix DKIM signing to always semicolon-terminate. Although the
RFC says it is optional some validators care. The missing char was not
- intended but triggered by a line-wrap alignement. Discovery and fix by
+ intended but triggered by a line-wrap alignment. Discovery and fix by
Guillaume Outters, hacked on by JH.
JH/18 Bug 2617: Fix a taint trap in parse_fix_phrase(). Previously when the
name being quoted was tainted a trap would be taken. Fix by using
- dynamicaly created buffers. The routine could have been called by a
+ dynamically created buffers. The routine could have been called by a
rewrite with the "h" flag, by using the "-F" command-line option, or
by using a "name=" option on a control=submission ACL modifier.
JH/30 Bug 2677: fix matching of long addresses. Since 4.93 a limit of 256 was
applied. This resulted, if any header-line rewrite rules were configured,
- in a panic-log trigerrable by sending a message with a long address in
- a header. Fix by increaing the arbitrary limit to larger than a single
+ in a panic-log triggerable by sending a message with a long address in
+ a header. Fix by increasing the arbitrary limit to larger than a single
(dewrapped) 5322 header line maximum size.
JH/31 The ESMTP option name advertised for the SUPPORT_EARLY_PIPE build option
is changed from X_PIPE_CONNECT to PIPE_CONNECT. This is in line with
RFC 6648 which deprecates X- options in protocols as a general practice.
Changeover between the implementations is handled by the mechanisms
- alrready coded.
+ already coded.
JH/32 Bug 2599: fix delay of delivery to a local address where there is also
a remote which uses callout/hold. Previously the local was queued.
JH/38 When logging an AUTH failure, as server, do not include sensitive
information. Previously, the credentials would be included if given
- as part of the AUTH command line and an ACL denied authentidcation.
+ as part of the AUTH command line and an ACL denied authentication.
JH/39 Bug 2691: fix $local_part_data. When the matching list element
referred to a file, bad data was returned. This likely also affected
previous coding assumed this would not happen, and under PIPELINING
would result in both lost and duplicate recipients for a message.
+JH/43 Bug 2694: Fix weighted distribution of work to multiple spamd servers.
+ Previously the weighting was incorrectly applied. Similar fix for socks
+ proxies. Found and fixed by Heiko Schlichting.
+
+JH/44 Bug 2701: Fix list-expansion of dns_ipv4_lookup. Previously, it did
+ not handle sub-lists included using the +namedlist syntax. While
+ investigating, the same found for dns_trust_aa, dns_again_means_nonexist,
+ dnssec_require_domains, dnssec_request_domains, srv_fail_domains,
+ mx_fail_domains.
+
+JH/45 Use a (new) separate store pool-pair for DKIM verify working data.
+ Previously the permanent pool was used, so the sore could not be freed.
+ This meant a connection with many messages would use continually-growing
+ memory.
+
+JH/46 Use an exponentially-increasing block size when malloc'ing store. Do it
+ per-pool so as not to waste too much space. Previously a constant size
+ was used which resulted in O(n^2) behaviour; now we get O(n log n) making
+ DOS attacks harder. The cost is wasted memory use in the larger blocks.
+
+JH/47 Use explicit alloc/free for DNS lookup workspace. This permits using the
+ same space repeatedly, and a smaller process footprint.
+
+JH/48 Use a less bogus-looking filename for a temporary used for DH-parameters
+ for GnuTLS. Previously the name started "%s" which, while not a bug,
+ looked as if if might be one.
+
+JH/49 Bug 2710: when using SOCKS for additional messages after the first (a
+ "continued connection") make the $proxy_* variables available. Previously
+ the information was not passed across the exec() call for subsequent
+ transport executions. This also mean that the log lines for the
+ messages can show the proxy information.
+JH/50 Bug 2672: QT elements in log lines, unless disabled, now exclude the
+ receive time. With modern systems the difference is significant.
+ The historical behaviour can be restored by disabling (a new) log_selector
+ "queue_time_exclusive".
+
+JH/51 Taint-check ACL line. Previously, only filenames (for out-of-line ACL
+ content) were specifically tested for. Now, also cover expansions
+ resulting in ACL names and inline ACL content.
+
+JH/52 Fix ${ip6norm:} operator. Previously, any trailing line text was dropped,
+ making it unusable in complex expressions.
+
+JH/53 Bug 2743: fix immediate-delivery via named queue. Previously this would
+ fail with a taint-check on the spoolfile name, and leave the message
+ queued.
+
+HS/01 Enforce absolute PID file path name.
+
+HS/02 Handle SIGINT as we handle SIGTERM: terminate the Exim process.
+
+PP/01 Add a too-many-bad-recipients guard to the default config's RCPT ACL.
+
+PP/02 Bug 2643: Correct TLS DH constants.
+ A missing NUL termination in our code-generation tool had led to some
+ incorrect Diffie-Hellman constants in the Exim source.
+ Reported by kylon94, code-gen tool fix by Simon Arlott.
+
+PP/03 Impose security length checks on various command-line options.
+ Fixes CVE-2020-SPRSS reported by Qualys.
+
+PP/04 Fix Linux security issue CVE-2020-SLCWD and guard against PATH_MAX
+ better. Reported by Qualys.
+
+PP/05 Fix security issue CVE-2020-PFPSN and guard against cmdline invoker
+ providing a particularly obnoxious sender full name.
+ Reported by Qualys.
+
+PP/06 Fix CVE-2020-28016 (PFPZA): Heap out-of-bounds write in parse_fix_phrase()
+
+PP/07 Refuse to allocate too little memory, block negative/zero allocations.
+ Security guard.
+
+PP/08 Change default for recipients_max from unlimited to 50,000.
+
+PP/09 Fix security issue with too many recipients on a message (to remove a
+ known security problem if someone does set recipients_max to unlimited,
+ or if local additions add to the recipient list).
+ Fixes CVE-2020-RCPTL reported by Qualys.
+
+PP/10 Fix security issue in SMTP verb option parsing
+ Fixes CVE-2020-EXOPT reported by Qualys.
+
+PP/11 Fix security issue in BDAT state confusion.
+ Ensure we reset known-good where we know we need to not be reading BDAT
+ data, as a general case fix, and move the places where we switch to BDAT
+ mode until after various protocol state checks.
+ Fixes CVE-2020-BDATA reported by Qualys.
+
+HS/03 Die on "/../" in msglog file names
+
+QS/01 Creation of (database) files in $spool_dir: only uid=0 or the uid of
+ the Exim runtime user are allowed to create files.
+
+QS/02 PID file creation/deletion: only possible if uid=0 or uid is the Exim
+ runtime user.
+
+QS/03 When reading the output from interpreted forward files we do not
+ pass the pipe between the parent and the interpreting process to
+ executed child processes (if any).
+
+QS/04 Always die if requested from internal logging, even is logging is
+ disabled.
+
+JH/54 DMARC: recent versions of the OpenDMARC library appear to have broken
+ the API; compilation noo longer completes with DMARC support included.
+ This affects 1.4.1-1 on Fedora 33 (1.3.2-3 is functional); and has
+ been reported on other platforms.
+
+JH/55 TLS: as server, reject connections with ALPN indicating non-smtp use.
+
+JH/56 Make the majority of info read from config files readonly, for defence-in-
+ depth against exploits. Suggestion by Qualys.
+ Not supported on Solaris 10.
+
+JH/57 Fix control=fakreject for a custom message containing tainted data.
+ Previously this resulted in a log complaint, due to a re-expansion present
+ since fakereject was originally introduced.
+
+JH/58 GnuTLS: Fix certextract expansion. If a second modifier after a tag
+ modifier was given, a loop resulted.
+
+JH/59 DKIM: Fix small-message verification under TLS with chunking. If a
+ pipelined SMTP command followed the BDAT LAST then it would be
+ incorrectly treated as part of the message body, causing a verification
+ fail.
+
+JH/60 Bug 2805: Fix logging of domain-literals in Message_ID: headers. They
+ require looser validation rules than those for 821-level addresses,
+ which only permit IP addresses.
Exim version 4.94
to do ARC verification. The Authentication-Results: header line added
by the configuration then had no ARC item.
+JH/48 Bug 2784: fix shutdown=no in the ${readsocket) expansion item. Previously
+ an incorrect mode was used for reading the result, resulting in it being
+ ignored.
+
Exim version 4.92
-----------------