Exim unable to send email with error "unable to set gid=544 or uid=18 after update

[Peter Senft <peter at dusares dot com>]

Hi,

I had a perfectly fine running exim configuration, that delivered mail
to a smart host and rewrote the sender address to be a specific one
(necessary for the smart host). Then, through the installation of some
additional tools, I also got an update for Exim (now Exim version 4.84
#1 built 25-Jan-2015 22:16:19). Since then I receive the following error
message, when I try to send emails:

-----> snip <-----
2015-04-24 14:20:21 unable to set gid=544 or uid=18 (euid=197108):
privilege not needed
-----> snap <-----

Google was no help at all here and all I got out of this was, that I
should not need the privilege because I have it already, but then it
fails to get the privilege. Very confusing and not helping at all.
Especially, when nothing changed but the update.

One thing that was odd though, was that the output of mkpasswd -l
changed. Some shell entries switched from /bin/false to /bin/bash. But I
tried both versions and neither one works. FYI, I renamed Administrator
to root in the passwd and group file.

The server runs as user cyg_server:

-----> snip <-----
$ id cyg_server
uid=197610(cyg_server) gid=197121(None) groups=11(Authenticated
Users),197121(None),544(root),545(Users)
-----> snap <-----

Then I checked what is in /etc/passwd:

-----> snip <-----
SYSTEM:*:18:18:U-NT AUTHORITY\SYSTEM,S-1-5-18:/home/SYSTEM:/bin/bash
LOCAL SERVICE:*:19:19:U-NT AUTHORITY\LOCAL SERVICE,S-1-5-19:/:/sbin/nologin
NETWORK SERVICE:*:20:20:U-NT AUTHORITY\NETWORK
SERVICE,S-1-5-20:/:/sbin/nologin
Administrators:*:544:544:U-BUILTIN\Administrators,S-1-5-32-544:/:/sbin/nologin
NT SERVICE+TrustedInstaller:*:328384:328384:U-NT
SERVICE\TrustedInstaller,S-1-5-80-956008885-3418522649-1831038044-1853292631-2271478464:/:/sbin/nologin
root:*:197108:197121:U-WINBUILD\Administrator,S-1-5-21-2134289365-1234066999-3699115456-500:/home/Administrator:/bin/bash
cyg_server:*:197610:197121:U-WINBUILD\cyg_server,S-1-5-21-2134289365-1234066999-3699115456-1002:/home/cyg_server:/bin/bash
Guest:*:197109:197121:U-WINBUILD\Guest,S-1-5-21-2134289365-1234066999-3699115456-501:/home/Guest:/bin/bash
-----> snap <-----

Then I checked what is in /etc/group:

-----> snip <-----
SYSTEM:S-1-5-18:18:
NT
SERVICE+TrustedInstaller:S-1-5-80-956008885-3418522649-1831038044-1853292631-2271478464:328384:
Access Control Assistance Operators:S-1-5-32-579:579:
root:S-1-5-32-544:544:
Backup Operators:S-1-5-32-551:551:
Certificate Service DCOM Access:S-1-5-32-574:574:
Cryptographic Operators:S-1-5-32-569:569:
Distributed COM Users:S-1-5-32-562:562:
Event Log Readers:S-1-5-32-573:573:
Guests:S-1-5-32-546:546:
Hyper-V Administrators:S-1-5-32-578:578:
IIS_IUSRS:S-1-5-32-568:568:
Network Configuration Operators:S-1-5-32-556:556:
Performance Log Users:S-1-5-32-559:559:
Performance Monitor Users:S-1-5-32-558:558:
Power Users:S-1-5-32-547:547:
Print Operators:S-1-5-32-550:550:
RDS Endpoint Servers:S-1-5-32-576:576:
RDS Management Servers:S-1-5-32-577:577:
RDS Remote Access Servers:S-1-5-32-575:575:
Remote Desktop Users:S-1-5-32-555:555:
Remote Management Users:S-1-5-32-580:580:
Replicator:S-1-5-32-552:552:
Users:S-1-5-32-545:545:
WinRMRemoteWMIUsers__:S-1-5-21-2134289365-1234066999-3699115456-1000:197608:
None:S-1-5-21-2134289365-1234066999-3699115456-513:197121:
-----> snap <-----

Any help here is greatly appreciated, because the same happened on
multiple machines at the same time.

Thanks,

Peter

-- 
/"\                        | Peter Senft
\ / ASCII ribbon campaign  | E-Mail : peter@dusares.com
 X  against HTML mail      | Jabber : dusares@jabber.org
/ \                        | ICQ    : 62090394

Attachment: signature.asc
Description: OpenPGP digital signature