OSEC

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RE: Microsoft Windows CreateRemoteThread Exploit

From: Michael Wojcik (Michael.Wojcikmicrofocus.com)
Date: Fri Dec 02 2005 - 08:41:18 CST


> From: q7xashiyane.com [mailto:q7xashiyane.com]
> Sent: Thursday, 01 December, 2005 05:02
>
> Description:
> when the one process open with OpenProcess function and
> use CreateRemoteThread(Process,0,0,x,0,0,0) then the process crash.
> an example hackers can use this method for kill firewalls
> and antiviruses

If an attacker can successfully call OpenProcess() on a process with
arbitrary access, then they can just request PROCESS_TERMINATE access
and terminate the process with TerminateProcsss(). Other attacks are
obviously possible with other forms of access.

I don't see how this particular feature is a vulnerability unless an
attacker can somehow perform a successful OpenProcess() but only with
PROCESS_CREATE_THREAD access. And even then, why couldn't the attacker
just do:

CreateRemoteThread(Process, NULL, 0, (LPTHREAD_START_ROUTINE)_exit,
NULL, 0, NULL);

or indeed create a remote thread with any other useful function the
process has mapped?

This "exploit" boils down to "if I can make a process call address 0, I
can cause an exception in it". Well, sure. If you can make a process
execute arbitrary code, you can do all sorts of things.

An attacker who can successfully open a security-critical process has
already won.

--
Michael Wojcik
Principal Software Systems Developer, Micro Focus