Le 01/06/2016 à 11:24, Jeremy Harris a écrit :
On 31/05/16 18:44, Samuel wrote:
2016-05-31 05:55:44 TLS error on connection from
researchscan258.eecs.XXXX.edu (eecs.XXXX.edu) [1XX.212.XXX.3]
(gnutls_handshake): Could not negotiate a supported cipher suite.
2016-05-31 05:55:44 H=researchscan258.eecs.XXXX.edu (eecs.XXXX.edu)
[1XX.212.XXX.3] Warning: erreur : tls-failed
OK, cipher-suite mismatch...
/var/log/syslog :
May 31 05:55:44 anemone-mailin-01 kernel: [4547900.677897] traps:
exim4[23055] general protection ip:6664ddc0bad6 sp:7483826d3710 error:0
in libc-2.19.so[6664ddba2000+1a2000]
Oops!
So if I understand well, A special craft ssl request can cause DOS on
Exim on Grsecurity kernel ?
Not all that crafted; just a choice of ciphers.
What can I do to stop this ?
Gather more information so that we can fix the bug where the crash is.
A full stack trace of the crash point, with debuginfo. Generally this
means enabling suid-process coredumps though, and this is a security
issue (the coredump potentially contains sensitive info, so you
don't want just anyone to be able to read the file).
Also: any idea if this was STARTTLS or SSL-on-connect?
Finally, as I answered in the list, the port 465 was closed, so sure it
was on the port 25 with starttls.
exim -d --version
Exim version 4.84_2 #1 built 13-Mar-2016 17:47:17
Many thanks for gathering that level of info - I wish more people did!
--
Cheers,
Jeremy
Thanks.
Samuel.
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