RE: [fw-wiz] RDP and security

From: Dan Harp (dan_at_brenius.com)
Date: 01/06/04

  • Next message: Timo Proescholdt: "RE: [fw-wiz] RDP and security"
    To: <firewall-wizards@nfr.com>
    Date: Tue, 6 Jan 2004 10:37:43 -0500
    
    

    Not sure how this specifically relates to firewalls...

    However, as stated by MS: "every version of RDP uses RSA Security’s RC4
    cipher, a stream cipher designed to efficiently encrypt small amounts of
    varying size data. RC4 is designed for secure communications over networks,
    and is also used in protocols such as SSL, which encrypts traffic to and
    from secure Web sites.

    In Windows 2000, administrators can choose to encrypt the data using a 56-
    or 128-bit key. Encryption is bi-directional except when using the ‘low’
    security setting that only encrypts data from the client to the server
    (which protects sensitive information such as passwords). The default
    setting is “medium” which uses a 56-bit key to bi-directionally encrypt the
    data. 128-bit encryption can be enabled after installing the Windows 2000
    High Encryption Pack."

    As previously stated, the largest flaw is the lack of pre-Windows
    authentication. For a more secure system, a non-Windows authentication
    should be first, and then once authenticated, access to the Terminal
    Services/Remote Desktop authentication process (connected to Windows
    authentication) should be granted.

    Without writing your own pre-authentication system, or involving a 3rd
    party, you could limit connections to TCP port 3389 based on allowed IP
    addresses at your firewall.

    Regards,

    - Dan

    > -----Original Message-----
    > From: firewall-wizards-admin@honor.icsalabs.com
    > [mailto:firewall-wizards-admin@honor.icsalabs.com] On Behalf
    > Of GChen@allianz.ca
    > Sent: January 6, 2004 9:21 AM
    > To: morty@frakir.org
    > Cc: firewall-wizards@nfr.com;
    > firewall-wizards-admin@honor.icsalabs.com; TSimons@Delphi-Tech.com
    > Subject: RE: [fw-wiz] RDP and security
    >
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    > Windows 2003 Server may fixed the issue. It supports SSL for
    > Terminal Services over the web.
    >
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    > TSimons@Delphi-Tech.com
    >
    >
    > Sent by:
    > To: morty@frakir.org
    >
    > firewall-wizards-admin@honor.i
    > cc: firewall-wizards@nfr.com
    >
    > csalabs.com
    > Subject: RE: [fw-wiz] RDP and security
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    > 01/05/2004 08:24 AM
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    > In our eyes the biggest design flaw is that there is no
    > authentication prior to the windows authentication. PCs in a
    > locked office are more secure than a Terminal Server out on
    > the public internet... because you need a key to get into the office.
    >
    > -----Original Message-----
    > From: Mordechai T. Abzug [mailto:morty@frakir.org]
    > Sent: Friday, November 21, 2003 12:48 AM
    > To: firewall-wizards@nfr.com
    > Subject: [fw-wiz] RDP and security
    >
    >
    >
    > Anyone have any strong opinions on the security of RDP
    > (Microsoft's terminal server/remote desktop protocol)?
    > Poking around on the net, I see that they've had at least one
    > design flaw that supposedly hasn't been fixed (ie. server
    > identification.) Any other design problems?
    >
    > Thanks!
    >
    > - Morty
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  • Next message: Timo Proescholdt: "RE: [fw-wiz] RDP and security"

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