COMMAND

    IE

SYSTEMS AFFECTED

    Win NT, 9x

PROBLEM

    Jan De Clercq observed the following strange behaviour of MS proxy
    server.

    Situation A
    -----------
    Using MS internet Explorer from  a client on internal network  you
    wish to connect a web  application somewhere on the web.   There's
    an MS  proxy server  2.0 between  your network  and the  internet.
    (the web  application supports  only basic  authentication).   You
    type in the web address of  the web server in your browser.   Your
    browser authenticates  you transparently  to MS  proxy using NTLM;
    once  on  the  web  server  the  web  application  asks  you   for
    credentials     (dialog     box     displays:         resource:web
    application/user:?/password:?);  you  fill  in  my web application
    credentials; directly afterwards you  get a new dialog  box asking
    you again for credentials but  this time to access your  own proxy
    server (resource: proxy server/user:?/password:?).

    Situation B
    -----------
    Same as  A but  this time  you use  Netscape Communicator; In this
    case your proxy first  asks you for credentials  (logical: because
    NTLM  authentication  is  not  supported by Communicator (however,
    there's an add-in)); afterwards  the web application asks  you for
    the other credentials (basic authentication).

    In situation B the proxy server  behaves as one would expect.   It
    is not logical that in situation A the proxy forgets the fact that
    you just authenticated using NTLM...(transparently).

SOLUTION

    This is  a know  feature of  IE 4.x  in combination  with Proxy 2.
    (it's a password caching problem of IE 4).  If you would test  the
    same with IE 3.x you won't have the problem.  Officialy  Microsoft
    deny the existance of this fix.  The fix is an update  WININET.DLL
    file.  It's a fix ontop of the SP1 of IE 4.01.  They (MS) say that
    it will not work with IE 4 only with IE 4.01SP1.  (BTW the file is
    called 2194.exe maybe with that name MS will give it to you too.)