VIGILANTE-2000012: Mdaemon Web Services Heap Overflow DoS

[Peter Gründl <prg () vigilante com>]

Mdaemon Web Services Heap Overflow DoS

Advisory Code:   VIGILANTE-2000012

Release Date:
September 18, 2000

Systems Affected:
- Mdaemon 3.1.1 for Windows NT
It is likely that older versions are also affected.

THE PROBLEM
We want to start off by pointing out that this is not the same problem
as was initially reported by USSR labs in Mdaemon 2.8.5.0:
http://www.ussrback.com/labs15.html.

The Mdaemon Worldclient on TCP port 3000 and the Mdaemon Webconfig on
TCP port 3001 both contain the same vulnerability. If a certain request
is sent to the web service, it results in a heap overflow, crashing the
service with a Dr. Watson access violation.

This appears to be a general problem in the way that Mdaemon handles
these kinds of URLs, so if other Mdaemon web services are used, those
are probably vulnerable as well. The reason that the before mentioned
services were tested is that they are enabled in a default installation.

A Side Note:
Even though this is "only" a Denial of Service, the fact is that it is
a heap overflow, and with several registers overwritten in a process
owned by LocalSystem, there is a possibility that it could be exploited
to gain elevated privileges on the host.

Vendor Status:
The vendor was contacted on the 12th of September and the vulnerability
was verified by them the following day. The fix was officially released
on the 14th of September. It's nice to see the vendor react so quickly.


Fix:
The fix is to upgrade to version 3.1.12, which can be found here:
ftp://ftp.altn.com/MDaemon/Release/md312.exe


Vendor   URL: http://www.altn.com
Product  URL: http://www.mdaemon.com
Copyright VIGILANTe 2000-09-12

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