First reflections on security of MSN Messenger

From: Dmitri Alperovitch (dmitriat_private)
Date: Thu Jul 22 1999 - 00:40:35 PDT

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    Hi.
    
    Having just downloaded and briefly examined the newly released Microsoft's
    MSN Messenger,
    (Microsoft's alternative to ICQ, AIM and other instant messaging clients) I
    must say that Microsoft
    has not learn a single thing from serious security design mistakes made by
    other instant
    messengers.  Here is a list of vulnerabilities that I have found in the
    first 30 minutes of using it:
    
    1.  Password (which is the same as your Hotmail e-mail password) and
    contact list are stored in
          the Registry (HKEY_CURRENT_USER\Identities).
          They are both stored as ASCII values in a binary field (Does
    Microsoft actually believe that
           such amateur trick is going to stop a serious hacker?)
    
    2. The instant messages are sent unencrypted in MIME format.  Curiously,
    there is a mention of
          "security software licensed from RSA Data Security, Inc" in the About
    box of the application
          and the program is apparently using Crypto API Hash functions for
    _something_ but it's unclear
          for which purpose.  It might actually send a password hash, instead
    of the real password, in it's
          communication with the server, but I have not been able to check that
    yet.
    
    3. The program is using Hotmail as its user base. So, if you do not have a
    Hotmail account,
          you apparently cannot use the program until you register one (nice
    marketing technique).
          However, this also presents a big security problem.  Hotmail has a
    policy to terminate user
          accounts after 120 days of inactivity. So, you might find yourself in
    a situation where you've
          been unable to access your Hotmail account for 3 months and someone
    else has registered your
          account and is impersonating you on MSN Messenger!
    
    These are only the most noticeable problems that I've discovered by just
    examining program's
    operation, the registry, and very briefly looking at the packets sent by
    the program.  A closer
    and more thorough examination of the packet exchange might reveal further
    and maybe even
    more serious security weaknesses.
    
    Yours truly,
    
    
    Dmitri Alperovitch
    Encryption Software - Developers of TSM for ICQ, an ICQ encryption add-on
    http://www.encrsoft.com
    dmitriat_private
    



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