We have an issue with Rexec server on IBMi as well.
We use IBM Rochester's FSFC Toolkit to flashcopy the all our LPAR
partitions
each evening. We then spin up the flashed system and backup the partition
to tape.
The FSFC toolkit uses the Rexec server to communicate between the
controlling partition and
the target partition for command and control. The credentials go in the
clear. When we scan
the network each IBMi shows critical vulnerabilities.
We had to write a rexec server exit to limit the systems and profiles that
were able to
access the rexec server.
We opened a ticket with IBM labs but they responded they had no plans to
change from rexec.
Jim
Jim W Grant
Senior VP, Chief Information Officer
Web: www.pdpgroupinc.com
From: John Yeung <gallium.arsenide@xxxxxxxxx>
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Date: 04/21/2016 05:40 PM
Subject: Re: XWindows service on IBM i
Sent by: "MIDRANGE-L" <midrange-l-bounces@xxxxxxxxxxxx>
On Thu, Apr 21, 2016 at 3:10 PM, Buck Calabro <kc2hiz@xxxxxxxxx> wrote:
On 4/21/2016 2:55 PM, Justin Dearing wrote:
Pretty rexec is part of rsh, unencrypted ssh. Don't use it. Password
transmitted in plain text.
This is a shut it of and see if people complain kind of thing because
it's
unpopular and insecure. I don't blame your auditors getting upset at
this.
CVE-1999-0526
CVSS v2 Base Score: 10.0 HIGH
See also: http://www.kb.cert.org/vuls/id/704969
I might get upset about rexec too, but the link points to X11 /
XWindows. Rexec isn't X11, is it? Is the CVE some confusion over port
numbers?
Right. It looks like either Rob or the auditors (or maybe both) have
had some kind of misunderstanding. X11 (formally the X Window System)
is unrelated to rexec or RUNRMTCMD. (Based on the link provided by
Chris, I think RUNRMTCMD *is* the midrange incarnation of Unix's
rexec, because they use the same commonly recognized port, and they
provide the same or very similar functionality.)
I can't say which is the "real" issue, but I can say with confidence
that RUNRMTCMD is discussed in these midrange lists far more often
than X11 is. And rexec is inherently insecure, whereas X11 can be used
in conjunction with SSH.
John Y.
midrange.com
