DATE:
COMMAND SOURCE:
AUTHOR:
IIS
SYSTEMS AFFECTED
Win NT Microsoft Internet Information Server 3.0
PROBLEM
Daragh Malone provided this information. It appears that any
Active Server Page can create, read, write or overwrite any file
on the system, regardless of security permissions. Here's how to
recreate the situation. Share out the wwwroot directory to a
user, or use InterDev and allow the user to login to the web.
This I would imagine is all that you want the user to see. If
this user creates an .asp page, and uses the
Scripting.FileSystemObject, he has full control over any file on
the machine.
For example:
<%
Set fsMad=CreateObject("Scripting.FileSystemObject")
Set fileMad=fsMad.CreateTextFile("c:\winnt\mad.txt")
fileMad.write("Here's a bit of a strange one")
fileMad.close
%>
Neither the users account or the IUSR_machinename account have
been granted the write to do this. It seems that the file is been
manipulated by the SYSTEM account.
This is probably by design, but D. Marone gave it here as a
warning that sharing out wwwroot is in effect sharing out the
entire filesystem.
EXPLOIT
SOLUTION
I'm sure that MS will make up sometning.