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:

http://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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