Changes in 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.
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