exim remote heap overflow, probably not exploitable

[Nick Cleaton <nick@xxxxxxxxxxx>]

Exim (www.exim.org) is a message transfer agent (MTA) developed
at the University of Cambridge for use on Unix systems connected
to the Internet.

There's a heap overflow in all versions of exim3 and exim4 prior
to version 4.21.  It can be exercised by anyone who can make an
SMTP connection to the exim daemon.

The overflow is very limited, and in my opinion it's probably not
exploitable.  However, it's possible that this will prove to be
exploitable for arbitrary command execution on some platforms in
some circumstances.

Patches:

  http://www.exim.org/pipermail/exim-announce/2003q3/000094.html

Full details coming soon to vuln-dev.

--
Nick Cleaton
nick@xxxxxxxxxxx