Re: FW: Windows Update - Unsafe ActiveX control (fwd)

From: Cesar (cesarc56at_private)
Date: Fri Jul 18 2003 - 10:15:06 PDT

  • Next message: Next Generation Insight Security Reseach Team: "[VulnWatch] Witango & Tango 2000 Application Server Remote System Buffer Overrun"

    Hi.
    
    I wouldn't consider Windows Update ActiveX as safe,
    the ActiveX has dangerous methods, for example it can
    reboot the computer. Of course the ActiveX checks for
    the current site and if it's not Windows Update site
    it won't work, but if there is some XSS hole in
    Windows Update site or if there is a bug in IE that
    allows to trick the URL, then the ActiveX becomes very
    dangerous. In my opinion restricting an ActiveX to a
    specific site only reduce the attack surface but it
    doesn't make an ActiveX safe.
    
    Cesar.
    --- Dave Ahmad <daat_private> wrote:
    > 
    > ---------- Forwarded message ----------
    > Date: Thu, 17 Jul 2003 XX:XX:XX
    > To: Dave Ahmad <daat_private>
    > Subject: FW: Windows Update - Unsafe ActiveX control
    > 
    > Hi,
    > 
    > I would prefer not to reply to this post directly,
    > but if possible can
    > you please mention the following (anonymously):
    > 
    > ----------
    > "Safe for Scripting" simply means that the control
    > is safe to be used
    > from untrusted callers. SFS controls can access
    > files and other
    > resources if it is in a controlled way (eg, with the
    > consent of the
    > user). Windows Update is safe because it only allows
    > itself to be hosted
    > from the Windows Update site. If you try and host
    > the control from
    > another domain, the control will not work. Since the
    > Windows Update site
    > only ever uses the control for "good" purposes, and
    > requires the user's
    > consent to install patches, etc. it is considered
    > "Safe for Scripting".
    > _All_ ActiveX controls can access memory and
    > registers directly, whether
    > they are marked as safe or not, since they typically
    > are implemented in
    > native code ;-)
    > 
    > Windows Update does not require you to run "unsafe"
    > controls;
    > unfortunately the generic error that appears when
    > you disable scripting
    > of _safe_ controls makes it sound like there are
    > _unsafe_ controls. If
    > you enable scripting of "safe" controls then the
    > site should work fine.
    > If you are concerned about securing the browser, I
    > recommend that you
    > place Windows Update in the "Trusted Sites" zone and
    > run that in the
    > "Medium" security mode, and run the rest of the
    > "Internet Zone" in
    > "High" mode, although this will break a lot of
    > sites.
    > 
    
    
    __________________________________
    Do you Yahoo!?
    SBC Yahoo! DSL - Now only $29.95 per month!
    http://sbc.yahoo.com
    



    This archive was generated by hypermail 2b30 : Fri Jul 18 2003 - 10:46:47 PDT