[ISN] Microsoft Security Bulletin (MS98-015) (Untrusted Scripted Paste IE 4.01)

From: mea culpa (jerichot_private)
Date: Fri Oct 16 1998 - 12:30:01 PDT

  • Next message: mea culpa: "[ISN] Hackers invade India Army Site"

    Forwarded From: Microsoft Product Security <secnotift_private>
    
    The following is a Security  Bulletin from the Microsoft Product Security
    Notification Service.
    
    Please do not  reply to this message,  as it was sent  from an unattended
    mailbox.
                        ********************************
    
    Microsoft Security Bulletin (MS98-015)
    ------------------------------------------------------------
    Update available for "Untrusted Scripted Paste" Issue in
    Microsoft Internet Explorer 4.01
    
    Originally Posted: October 16, 1998
    Last Revised: October 16, 1998
    
    Summary
    =======
    Microsoft has released a patch that fixes a vulnerability involving scripted
    pastes that has been discovered with Internet Explorer 4.01 on Win32 and
    Win16 platforms. The vulnerability could make it possible for a malicious
    hacker to create a web site that, when visited, is able to use script to
    read a file on the user's system. The file must be in a location known to
    the malicious hacker. This has also been referred to as the "Cuartango"
    vulnerability.
    
    Microsoft highly recommends that users that have affected software installed
    on their systems should download and install the available patch as soon as
    possible.
    
    Issue
    =====
    The "Untrusted Scripted Paste" issue involves a vulnerability in Internet
    Explorer that could allow a malicious hacker to circumvent certain Internet
    Explorer security safeguards. This vulnerability makes it possible for a
    malicious Web site operator to read the contents of a file on the user's
    computer if the hacker knows the exact name and path of the targeted file.
    This could also be used to view the contents of a file on the user's network
    to which the user has access, and whose direct path name is known by the
    attacker.
    
    The nature of this problem is that a script is able to use the
    Document.ExecCommand function to paste a filename into the file upload
    intrinsic control, which should only be possible by explicit user action. As
    a result, a subsequent form submission could send the file to a remote web
    site unbeknownst to the user if the user has disabled the default warning
    that is displayed when submitting unencrypted forms (see "Administrative
    Workaround" below for information on re-enabling this functionality).
    
    While there have not been any reports of customers being adversely affected
    by these problems, Microsoft is releasing a patch to address any risks posed
    by this issue.
    
    Affected Software Versions
    ==========================
     - Microsoft Internet Explorer 4.01 and 4.01 SP1
       on Windows NT 4.0, Windows 95
     - Microsoft Windows 98, with integrated Internet Explorer
     - Microsoft Internet Explorer 4.01 for Windows 3.1 and Windows NT 3.51
    
    This vulnerability could also affect software that uses HTML functionality
    provided by Internet Explorer, even if Internet Explorer is not used as your
    default browser. All customers that have affected versions of Internet
    Explorer on their systems should install this patch, whether or not they use
    Internet Explorer for web browsing.
    
    This vulnerability does not affect Internet Explorer 3.x or 4.0 on any
    platform.
    This does not affect any Macintosh or UNIX versions of Internet Explorer.
    
    What Microsoft is Doing
    =======================
    On October 16th Microsoft released a patch that fixes the problem
    identified. This patch is available for download from the sites listed
    below.
    
    Microsoft has sent this security bulletin to customers subscribing to the
    Microsoft Product Security Notification Service (see
    http://www.microsoft.com/security/bulletin.htm for more information about
    this free customer service).
    
    Microsoft has published the following Knowledge Base (KB) articles on this
    issue:
     - Microsoft Knowledge Base (KB) article Q169245,
       Update available for "Untrusted Scripted Paste" Issue
       http://support.microsoft.com/support/kb/articles/q169/2/45.asp
    
    What customers should do
    ========================
    Microsoft highly recommends that users that have affected software installed
    on their systems should download and install the available patch as soon as
    possible. Complete URLs for each affected software version is given below.
    
    Windows 98
    ----------
    Windows 98 customers can obtain the patch using Windows Update. To obtain
    this patch using Windows Update, launch Windows Update from the Windows
    Start Menu and click "Product Updates." When prompted, select 'Yes' to allow
    Windows Update to determine whether this patch and other updates are needed
    by your computer. If your computer does need this patch, you will find it
    listed under the "Critical Updates" section of the page.
    
    Internet Explorer 4.01
    ----------------------
    Customers using Internet Explorer 4.01 can obtain the patch from the
    Internet Explorer Security web site,
    http://www.microsoft.com/ie/security/paste.htm
    
    Administrative workaround
    =========================
    Microsoft strongly encourages customers to apply the patch. However, there
    are additional actions that can be taken to ensure safe computing:
    
    If the user has disabled the default warning that is displayed when
    submitting unencrypted forms, re-enabling this feature can provide
    additional protection. This warning prompt makes sure users are aware if a
    script attempts to submit data using forms. Users should be cautious if they
    see this warning when browsing and have not actually chosen to submit any
    data.
    
    To turn on this prompt:
    1. From Internet Explorer, choose "Internet Options" form the
       "View" menu.
    2. Click on the tab labeled "Security".
    3. Click on "Internet Zone", then click "Customize Settings".
    4. Scroll to "Submit non-encrypted form data" and click on
       "Prompt" (or "Disable" if you prefer).
    
    These same procedures should be followed for the "Restricted Sites" Zone.
    
    Additionally, users who cannot apply the patch immediately can disable
    Active Scripting technologies in Internet Explorer to protect themselves
    from this issue. Customers can use the Zones security feature in Internet
    Explorer 4 to disable Active Scripting (VBScript and JScript) in untrusted
    or unknown Internet sites, while still permitting known and trusted sites
    that use JScript and VBScript to work properly.
    
    To turn off Active Scripting for the "Internet" Zone:
    1. From Internet Explorer, choose "Internet Options" from
       the "View" menu.
    2. Click on the tab labeled "Security".
    3. Click on "Internet Zone", then click "Customize Settings".
    4. Scroll to the bottom of the list and click on "Disable"
       under the "Active Scripting" setting.
    5. These same procedures should be followed for the
       "Restricted Sites" Zone.
    
    Sites that are trusted to use JScript and VBScript can be added to the
    Trusted Zones list. For more information on using Zones, please see the
    Online Help included with Internet Explorer.
    
    More Information
    ================
    Please see the following references for more information related to this
    issue.
    
     - Microsoft Security Bulletin MS98-015,
       Update available for "Untrusted Scripted Paste" Issue
       in Microsoft Internet Explorer 4.01, (the Web posted
       version of this bulletin),
       http://www.microsoft.com/security/bulletins/ms98-015.htm
     - Microsoft Knowledge Base (KB) article Q169245,
       Update available for "Untrusted Scripted Paste" Issue
       http://support.microsoft.com/support/kb/articles/q169/2/45.asp
    
    Obtaining Support on this Issue
    ===============================
    This is a supported patch for Internet Explorer. If you have problems
    installing this patch or require technical assistance with this patch,
    please contact Microsoft Technical Support. For information on contacting
    Microsoft Technical Support, please see
    http://support.microsoft.com/support/contact/default.asp
    
    Acknowledgements
    ================
    This bug was first reported by Juan Carlos Garcia Cuartango from Spain.
    
    Revisions
    =========
     - October 16, 1998: Bulletin Created
    
    For additional security-related information about Microsoft products, please
    visit http://www.microsoft.com/security
    
    ------------------------------------------------------------
    
    THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS"
    WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER
    EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS
    SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT,
    INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN
    IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR
    LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE
    FOREGOING LIMITATION MAY NOT APPLY.
    
    
    (c) 1998 Microsoft and/or its suppliers. All rights reserved.
    For Terms of Use see http://support.microsoft.com/support/misc/cpyright.asp.
    
       *******************************************************************
    You have received  this e-mail bulletin as a result  of your registration
    to  the   Microsoft  Product  Security  Notification   Service.  You  may
    unsubscribe from this e-mail notification  service at any time by sending
    an  e-mail  to  MICROSOFT_SECURITY-SIGNOFF-REQUESTt_private
    The subject line and message body are not used in processing the request,
    and can be anything you like.
    
    For  more  information on  the  Microsoft  Security Notification  Service
    please    visit    http://www.microsoft.com/security/bulletin.htm.    For
    security-related information  about Microsoft products, please  visit the
    Microsoft Security Advisor web site at http://www.microsoft.com/security.
    
    -o-
    Subscribe: mail majordomot_private with "subscribe isn".
    Today's ISN Sponsor: Repent Security Incorporated [www.repsec.com]
    



    This archive was generated by hypermail 2b30 : Fri Apr 13 2001 - 13:07:54 PDT