FedCIRC Advisory FA-99-09
                                       
   Revised: June 18, 1999
   Originally released: June 16, 1999
   Source: CERT/CC
   
  Systems Affected
  
     * Machines running Microsoft Internet Information Server 4.0
       
I. Description

   Buffer overflow vulnerabilities affecting Microsoft Internet
   Information Server 4.0 have been discovered in several libraries,
   including libraries that handle .HTR, .STM, and .IDC files.
   
   A tool to exploit at least one of the vulnerabilities has been
   publicly released.
   
II. Impact

   These vulnerabilities allow remote intruders to execute arbitrary code
   with the privileges of the IIS server. Additionally, intruders can use
   this vulnerability to crash vulnerable IIS processes.
   
III. Solution

   Microsoft has released and updated Microsoft Security Bulletin
   MS99-019, which points to a patch for these vulnerabilities. We
   encourage you to read this bulletin, available from
   
   [1]http://www.microsoft.com/security/bulletins/ms99-019.asp
          
   We will update this advisory as more information becomes available.
   Please check the CERT/CC Web site for the most current revision.
     _________________________________________________________________
   
   Our thanks to Jason Garms and Scott Culp of Microsoft for providing
   information contained in this advisory.
   ______________________________________________________________________
   
   This document is available from:
   [2]http://www2.fedcirc.gov/advisories/FA-99-09.html
   ______________________________________________________________________
   
FedCIRC Contact Information

   Email: [3]fedcirc@fedcirc.gov
          Phone: +1 888-282-0870 (24-hour toll-free hotline)
          Phone: +1 412-268-6321 (24-hour hotline)
          Fax: +1 412-268-6989
          Postal address:
          FedCIRC CERT Coordination Center
          Software Engineering Institute
          Carnegie Mellon University
          Pittsburgh PA 15213-3890
          U.S.A.
          
   FedCIRC personnel answer the hotline 08:00-20:00 EST(GMT-5) /
   EDT(GMT-4) Monday through Friday; they are on call for emergencies
   during other hours, on U.S. holidays, and on weekends.
   
    Using encryption
    
   We strongly urge you to encrypt sensitive information sent by email.
   Our public PGP key is available from
   
   [4]http://www2.fedcirc.gov/keys.html
       
   If you prefer to use DES, please call the FedCIRC hotline for more
   information.
   
    Getting security information
    
   FedCIRC publications and other security information are available from
   our web site
   
   [5]http://www.fedcirc.gov/
       
   FedCIRC (Federal Computer Incident Response Capability) is operated by
   the CERT/CC for the U.S. General Services Administration. FedCIRC
   provides security services to U.S. Federal civilian agencies.
   
   Copyright 1999 Carnegie Mellon University.
   Conditions for use, disclaimers, and sponsorship information can be
   found in
   
   [6]http://www.cert.org/legal_stuff.html
       
   * "CERT" and "CERT Coordination Center" are registered in the U.S.
   Patent and Trademark Office.
   ______________________________________________________________________
   
   NO WARRANTY
   Any material furnished by Carnegie Mellon University and the Software
   Engineering Institute is furnished on an "as is" basis. Carnegie
   Mellon University makes no warranties of any kind, either expressed or
   implied as to any matter including, but not limited to, warranty of
   fitness for a particular purpose or merchantability, exclusivity or
   results obtained from use of the material. Carnegie Mellon University
   does not make any warranty of any kind with respect to freedom from
   patent, trademark, or copyright infringement.
   Revision History

June 16, 1999:  Initial release
June 18, 1999:  Added information about .STM and .IDC files.

References

   1. http://www.microsoft.com/security/bulletins/ms99-019.asp
   2. http://www2.fedcirc.gov/advisories/FA-99-09.html
   3. mailto:fedcirc@fedcirc.gov
   4. http://www2.fedcirc.gov/keys.html
   5. http://www.fedcirc.gov/
   6. http://www.cert.org/legal_stuff.html