+ from a dnsdb PTR lookup with an IPv6 address that had more than 8
+ components; fortuitously, this particular loophole had already been fixed
+ by change 4.50/55 above.
+
+ If there are any other similar loopholes, the new check in host_aton()
+ itself should stop them being exploited. The report I received stated that
+ data on the command line could provoke the exploit when Exim was running as
+ exim, but did not say which command line option was involved. All I could
+ find was the use of -be with a bad dnsdb PTR lookup, and in that case it is
+ running as the user.
+ CAN-2005-0021
+
+61. There was a buffer overflow vulnerability in the SPA authentication code
+ (which came originally from the Samba project). I have added a test to the
+ spa_base64_to_bits() function which I hope fixes it.
+ CAN-2005-0022
+
+62. Configuration update for GNU/Hurd and variations. Updated Makefile-GNU and
+ os.h-GNU, and added configuration files for GNUkFreeBSD and GNUkNetBSD.
+
+63. The daemon start-up calls getloadavg() while still root for those OS that
+ need the first call to be done as root, but it missed one case: when
+ deliver_queue_load_max is set with deliver_drop_privilege. This is
+ necessary for the benefit of the queue runner, because there is no re-exec
+ when deliver_drop_privilege is set.
+
+64. A call to exiwhat cut short delays set up by "delay" modifiers in ACLs.
+ This has been fixed.
+
+65. Caching of lookup data for "hosts =" ACL conditions, when a named host list
+ was in use, was not putting the data itself into the right store pool;
+ consequently, it could be overwritten for a subsequent message in the same
+ SMTP connection. (Fix 4.40/11 dealt with the non-cache case, but overlooked
+ the caching.)
+
+66. Added hosts_max_try_hardlimit to the smtp transport, default 50.
+
+67. The string_is_ip_address() function returns 0, 4, or 6, for "no an IP
+ address", "IPv4 address", and "IPv6 address", respectively. Some calls of
+ the function were treating the return as a boolean value, which happened to
+ work because 0=false and not-0=true, but is not correct code.
+
+68. The host_aton() function was not handling scoped IPv6 addresses (those
+ with, for example, "%eth0" on the end) correctly.
+
+69. Fixed some compiler warnings in acl.c for the bitmaps specified with
+ negated items (that is, ~something) in unsigned ints. Some compilers
+ apparently mutter when there is no cast.
+
+70. If an address verification called from an ACL failed, and did not produce a
+ user-specific message (i.e. there was only a "system" message), nothing was
+ put in $acl_verify_message. In this situation, it now puts the system
+ message there.
+
+71. Change 4.23/11 added synchronization checking at the start of an SMTP
+ session; change 4.31/43 added the unwanted input to the log line - except
+ that it did not do this in the start of session case. It now does.
+
+72. After a timeout in a callout SMTP session, Exim still sent a QUIT command.
+ This is wrong and can cause the other end to generate a synchronization
+ error if it is another Exim or anything else that does the synchronization
+ check. A QUIT command is no longer sent after a timeout.
+
+73. $host_lookup_deferred has been added, to make it easier to detect DEFERs
+ during host lookups.
+
+74. The defer_ok option of callout verification was not working if it was used
+ when verifying addresses in header lines, that is, for this case:
+
+ verify = header_sender/callout=defer_ok
+
+75. A backgrounded daemon closed stdin/stdout/stderr on entry; this meant that
+ those file descriptors could be used for SMTP connections. If anything
+ wrote to stderr (the example that came up was "warn" in embedded Perl), it
+ could be sent to the SMTP client, causing chaos. The daemon now opens
+ stdin, stdout, and stderr to /dev/null when it puts itself into the
+ background.
+
+76. Arrange for output from Perl's "warn" command to be written to Exim's main
+ log by default. The user can override this with suitable Perl magic.
+
+77. The use of log_message on a "discard" ACL verb, which is supposed to add to
+ the log message when discard triggers, was not working for the DATA ACL or
+ for the non-SMTP ACL.
+
+
+----------------------------------------------------
+See the note above about the 4.44 and 4.50 releases.
+----------------------------------------------------
+
+
+Exim version 4.44
+-----------------
+
+ 1. Change 4.43/35 introduced a bug that caused file counts to be
+ incorrectly computed when quota_filecount was set in an appendfile
+ transport
+
+ 2. Closing a stable door: arrange to panic-die if setitimer() ever fails. The
+ bug fixed in 4.43/37 would have been diagnosed quickly if this had been in
+ place.
+
+ 3. Give more explanation in the error message when the command for a transport
+ filter fails to execute.
+
+ 4. There are several places where Exim runs a non-Exim command in a
+ subprocess. The SIGUSR1 signal should be disabled for these processes. This
+ was being done only for the command run by the queryprogram router. It is
+ now done for all such subprocesses. The other cases are: ${run, transport
+ filters, and the commands run by the lmtp and pipe transports.
+
+ 5. Some older OS have a limit of 256 on the maximum number of file
+ descriptors. Exim was using setrlimit() to set 1000 as a large value
+ unlikely to be exceeded. Change 4.43/17 caused a lot of logging on these
+ systems. I've change it so that if it can't get 1000, it tries for 256.
+
+ 6. "control=submission" was allowed, but had no effect, in a DATA ACL. This
+ was an oversight, and furthermore, ever since the addition of extra
+ controls (e.g. 4.43/32), the checks on when to allow different forms of
+ "control" were broken. There should now be diagnostics for all cases when a
+ control that does not make sense is encountered.
+
+ 7. $recipients is now available in the predata ACL (oversight).
+
+ 8. Tidy the search cache before the fork to do a delivery from a message
+ received from the command line. Otherwise the child will trigger a lookup
+ failure and thereby defer the delivery if it tries to use (for example) a
+ cached ldap connection that the parent has called unbind on.
+
+ 9. If verify=recipient was followed by verify=sender in a RCPT ACL, the value
+ of $address_data from the recipient verification was clobbered by the
+ sender verification.
+
+10. If FIXED_NEVER_USERS was defined, but empty, Exim was assuming the uid 0
+ was its contents. (It was OK if the option was not defined at all.)
+
+11. A "Completed" log line is now written for messages that are removed from
+ the spool by the -Mrm option.
+
+12. $host_address is now set to the target address during the checking of
+ ignore_target_hosts.
+
+13. When checking ignore_target_hosts for an ipliteral router, no host name was
+ being passed; this would have caused $sender_host_name to have been used if
+ matching the list had actually called for a host name (not very likely,
+ since this list is usually IP addresses). A host name is now passed as
+ "[x.x.x.x]".
+
+14. Changed the calls that set up the SIGCHLD handler in the daemon to use the
+ code that specifies a non-restarting handler (typically sigaction() in
+ modern systems) in an attempt to fix a rare and obscure crash bug.
+
+15. Narrowed the window for a race in the daemon that could cause it to ignore
+ SIGCHLD signals. This is not a major problem, because they are used only to
+ wake it up if nothing else does.
+
+16. A malformed maildirsize file could cause Exim to calculate negative values
+ for the mailbox size or file count. Odd effects could occur as a result.
+ The maildirsize information is now recalculated if the size or filecount
+ end up negative.
+
+17. Added HAVE_SYS_STATVFS_H to the os.h file for Linux, as it has had this
+ support for a long time. Removed HAVE_SYS_VFS_H.
+
+18. Updated exipick to current release from John Jetmore.
+
+19. Allow an empty sender to be matched against a lookup in an address list.
+ Previously the only cases considered were a regular expression, or an
+ empty pattern.
+
+20. Exim went into a mad DNS lookup loop when doing a callout where the
+ host was specified on the transport, if the DNS lookup yielded more than
+ one IP address.
+
+21. The RFC2047 encoding function was originally intended for short strings
+ such as real names; it was not keeping to the 75-character limit for
+ encoded words that the RFC imposes. It now respects the limit, and
+ generates multiple encoded words if necessary. To be on the safe side, I
+ have increased the buffer size for the ${rfc2047: expansion operator from
+ 1024 to 2048 bytes.
+
+22. Failure to deliver a bounce message always caused it to be frozen, even if
+ there was an errors_to setting on the router. The errors_to setting is now
+ respected.
+
+23. If an IPv6 address is given for -bh or -bhc, it is now converted to the
+ canonical form (fully expanded) before being placed in
+ $sender_host_address.
+
+24. Updated eximstats to version 1.33
+
+25. Include certificate and key file names in error message when GnuTLS fails
+ to set them up, because the GnuTLS error message doesn't include the name
+ of the failing file when there is a problem reading it.
+
+26. Expand error message when OpenSSL has problems setting up cert/key files.
+ As per change 25.
+
+27. Reset the locale to "C" after calling embedded Perl, in case it was changed
+ (this can affect the format of dates).
+
+28. exim_tidydb, when checking for the continued existence of a message for
+ which it has found a message-specific retry record, was not finding
+ messages that were in split spool directories. Consequently, it was
+ deleting retry records that should have stayed in existence.
+
+29. eximstats updated to version 1.35
+ 1.34 - allow eximstats to parse syslog lines as well as mainlog lines
+ 1.35 - bugfix such that pie charts by volume are generated correctly
+
+30. The SPA authentication driver was not abandoning authentication and moving
+ on to the next authenticator when an expansion was forced to fail,
+ contradicting the general specification for all authenticators. Instead it
+ was generating a temporary error. It now behaves as specified.
+
+31. The default ordering of permitted cipher suites for GnuTLS was pessimal
+ (the order specifies the preference for clients). The order is now AES256,
+ AES128, 3DES, ARCFOUR128.
+
+31. Small patch to Sieve code - explicitly set From: when generating an
+ autoreply.
+
+32. Exim crashed if a remote delivery caused a very long error message to be
+ recorded - for instance if somebody sent an entire SpamAssassin report back
+ as a large number of 550 error lines. This bug was coincidentally fixed by
+ increasing the size of one of Exim's internal buffers (big_buffer) that
+ happened as part of the Exiscan merge. However, to be on the safe side, I
+ have made the code more robust (and fixed the comments that describe what
+ is going on).
+
+33. Some experimental protocols are using DNS PTR records for new purposes. The
+ keys for these records are domain names, not reversed IP addresses. The
+ dnsdb PTR lookup now tests whether its key is an IP address. If not, it
+ leaves it alone. Component reversal etc. now happens only for IP addresses.
+ CAN-2005-0021
+
+34. The host_aton() function is supposed to be passed a string that is known
+ to be a valid IP address. However, in the case of IPv6 addresses, it was
+ not checking this. This is a hostage to fortune. Exim now panics and dies
+ if the condition is not met. A case was found where this could be provoked
+ from a dnsdb PTR lookup with an IPv6 address that had more than 8
+ components; fortuitously, this particular loophole had already been fixed
+ by change 4.50/55 or 4.44/33 above.
+
+ If there are any other similar loopholes, the new check in host_aton()
+ itself should stop them being exploited. The report I received stated that
+ data on the command line could provoke the exploit when Exim was running as
+ exim, but did not say which command line option was involved. All I could
+ find was the use of -be with a bad dnsdb PTR lookup, and in that case it is
+ running as the user.
+ CAN-2005-0021
+
+35. There was a buffer overflow vulnerability in the SPA authentication code
+ (which came originally from the Samba project). I have added a test to the
+ spa_base64_to_bits() function which I hope fixes it.
+ CAN-2005-0022
+
+36. The daemon start-up calls getloadavg() while still root for those OS that
+ need the first call to be done as root, but it missed one case: when
+ deliver_queue_load_max is set with deliver_drop_privilege. This is
+ necessary for the benefit of the queue runner, because there is no re-exec
+ when deliver_drop_privilege is set.
+
+37. Caching of lookup data for "hosts =" ACL conditions, when a named host list
+ was in use, was not putting the data itself into the right store pool;
+ consequently, it could be overwritten for a subsequent message in the same
+ SMTP connection. (Fix 4.40/11 dealt with the non-cache case, but overlooked
+ the caching.)
+
+38. Sometimes the final signoff response after QUIT could fail to get
+ transmitted in the non-TLS case. Testing !tls_active instead of tls_active
+ < 0 before doing a fflush(). This bug looks as though it goes back to the
+ introduction of TLS in release 3.20, but "sometimes" must have been rare
+ because the tests only now provoked it.