Group membership / Kerberos tickets

From: Zack Schiel (ZSchiel_at_blueandco.com)
Date: 04/28/05

  • Next message: Laura A. Robinson: "RE: Group membership / Kerberos tickets" 
    Date: Thu, 28 Apr 2005 09:51:58 -0500
To: <focus-ms@securityfocus.com>

    I'm hoping that someone here can confirm this for me and possibly give a deeper explanation for the behavior that we're seeing.

    Essentially, we are in the process of creating a series of site GPOs; the default Authenticated Users permission remains, and we've also denied Read and Apply Group Policy to a new group containing certain computers, mainly servers.  The problem that we're running into is that these servers don't appear in RSoP reports as members of the new security group (even though they have been for nearly 24 hours now), and thus they are receiving and applying these GPOs.  When the machines are rebooted, they correctly add the group to their list of security groups to which they belong, and the GPOs are denied. 

    The obvious solution is to reboot the servers before linking the GPO.  We would of course prefer to avoid rebooting dozens of servers, however. 

    I believe the reason this happens is that a machine receives its TGT at startup, and the TGT contains SIDs for groups to which the machine belongs.  This TGT is then simply renewed every X number of hours for several days, and thus the list of SIDs isn't updated until the ticket is actually reissued at restart.  Am I on the right track here?  Is there a relatively easy way to force a machine to reissue its TGT without rebooting or causing other issues? 

    Aside from our current predicament, this seems to be a bit of a security hole-machines can actively receive GPOs to which they have been denied access, long after they are denied that access. 

    Thanks,

    -Zack-

    ______________________
    Zack Schiel
    Network Support
    Blue & Co., LLC

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  • Next message: Laura A. Robinson: "RE: Group membership / Kerberos tickets"

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