NEWS: IE Scripting Flaw Uncovered
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Thread: NEWS: IE Scripting Flaw Uncovered

  1. #1
    Fastest Thing Alive s0nIc's Avatar
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    Cool NEWS: IE Scripting Flaw Uncovered

    Security researchers yesterday released details of a cross domain scripting flaw in Internet Explorer ahead of a fix by Microsoft.

    The flaw leaves applications that use WebBrowser control, including Microsoft IE, Outlook and Outlook Express (when run outside restricted zones), vulnerable to a variety of attacks, researchers from security consultancy PivX say.

    Possible exploits include elevating privileges, arbitrary command execution, local file reading and stealing arbitrary cookies.

    The vulnerability arises because the object property of embedded WebBrowser controls, which is used to embed external objects inside a page, is not subject to the cross domain security checks which embedded HTML documents ordinarily go through. It is explained in greater detail here.

    The upshot is that it's possible for crackers to construct exploits which escape any sandboxing and security zone restrictions. Such objects can be the WebBrowser control and other ActiveX controls, images or applets.

    PivX have put together a series of proof of concept exploits to back up their warning. The vulnerability was notified to Microsoft on June 25 but Redmond has yet to develop a fix

    To guard against the vulnerability, PivX suggests that administrators should disable ActiveX scripting until a patch is available.

    The release of information about vulnerabilities has been a point of contention between independent security vendors and vendors, most notably Microsoft, recently. Research by the Hurwitz Group, released late last month, suggests users would like to see information disclosed full disclosure of security information.

    PivX said it had decided to release information on this vulnerability following our report on this research.

    Source: http://www.theregister.co.uk/content/55/26147.html

    A follow up for those who wants MORE details on the flaw including the said exploit codes..

    ----------------------
    Affected applications:
    ----------------------

    Any application that hosts the WebBrowser control. Some of these are:

    Microsoft Internet Explorer
    Microsoft Outlook
    Microsoft Outlook Express

    Impact:
    -------

    Elevating privileges, arbitrary command execution, local file reading, stealing arbitrary cookies, etc.



    Authors:
    --------

    Patrick Zumstein and Thor Larholm.

    Introduction:
    -------------

    One of the many elements in HTML 4 is the OBJECT element which is used to embed external objects inside a page. Such objects can be the WebBrowser control and other ActiveX controls, images, applets and more. The object property of embedded WebBrowser controls is not subject to the Cross Domain security checks that embedded HTML documents ordinarily go through, and as such it is possible to escape any sandboxing and security zone restrictions.

    Discussion:
    -----------

    Any document can extend the properties exposed by the OBJECT element, and any namespace conflicts are handled by querying the object property which is a duplicate reference to the embedded document. When embedding a document from the same site (same protocol, port and host) it is possible to make a reference to the object property without circumventing any Cross Domain security checks. After having established a reference we will then change the location of the document being embedded. The location changes but the reference stays, and we now have complete access to the DOM of the foreign document.
    The default object being referenced by the object property in the case of text/html is the document object. The simple proof-of-concept exploit below will read the cookie from passport.com.

    The OBJECT element is not restricted to embedding HTML documents, but can embed objects of any type. As such, this vulnerability could be extended even further.

    Code:
    Exploit:
    --------
    var ref=document.getElementById("data").object;
    ref.location.href = "http://www.passport.com";
    setTimeout("alert(ref.cookie)",5000);
    Solution:
    ---------------------

    Disable ActiveX, or
    Set "Script ActiveX controls marked safe for scripting" to Prompt or Disable
    ( ).

    Tested on:
    ----------

    IE6 Win2000, all patches and servicepacks.
    IE5.5 Win98, all patches and servicepacks.
    IE5.5 WinNT 4, all patches and servicepacks.


    Demonstration:
    --------------

    I have put together some proof-of-concept examples:

    - Read foreign cookies
    - Read local (or foreign) file
    - Execute arbitrary commands

    These can be found at http://www.PivX.com/larholm/adv/TL003/

    Vendor status:
    --------------

    Microsoft was notified 25 June 2002.

    Mitigating factors:
    -------------------

    Outlook and OE are not directly affected if they run in the Restricted zone.

    Postscript:
    -----------

    On June 25, Patrick Zumstein notified Thor Larholm, Georgi Guninski and PacketStormSecurity about a possible vulnerability. In working together, Patrick and Thor quickly outlined the culprit and prepared this advisory, after which Microsoft were notified immediately. Since this is possibly very publicly known by now I have decided to release this advisory after only 2 weeks times, so that system administrators and end users may possibly apply the provided workaround to temporarily secure themselves until a proper patch has been made.


    Regards
    Thor Larholm, Security Researcher
    PivX Solutions, LLC

    Unpatched IE security holes - 19 and counting
    http://www.PivX.com/larholm/unpatched/
    Are You Secure?
    http://www.PivX.com

    Source: http://www.xatrix.org/article1700.html

  2. #2
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    thank you

  3. #3
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    Thank you for that info, s0nIc.

  4. #4
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    lol MS IE is such a joke, the security is pitiful. 19 unpatched *KNOWN* flaws!!! How many unknown, or unannounced flaws? This is rediculous. If only the average PC user would realize how insecure IE is, atleast get rid of that, then we'll work on *NIX
    Search First Ask Second. www.google.com

  5. #5
    Old-Fogey:Addicts founder Terr's Avatar
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    The 'average' user has a higher chance in a Linux week of locking themselves out of their box and having their whole (ext2) filesystem riddled with errors than accomplishing as much as they do in a normal day in windows.

    Notice that these flaws involve Microsoft Applications, rather than the OS... (At least, unless you believe MS in that they are totally integrated... hah.)

    I take the middle road.
    [HvC]Terr: L33T Technical Proficiency

  6. #6
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    an interesting exploit by japanese security enthusiasts: http://securityfriday.com/ToolDownlo.../ieen_doc.html






















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