Re: Vulnerability in HP OpenMail

From: Richi Jennings (richiat_private)
Date: Thu Apr 23 1998 - 06:31:07 PDT

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    dej wrote...
    
    > The good news is that mail users have their own Unix UIDs on the server.
    > The real problem is situations where the sysadmin has denied users regular
    > login access to the mail server, possibly by putting "*" in the password
    > field.  This is standard practice as a security measure.  If you have done
    > this on your OpenMail server, then you may want to check your security
    > measures carefully - your users can get the equivalent of shell whether you
    > allow it or not.
    
    This is a generic issue with any program that permits shell escapes.  It is
    generally-accepted good practice to set up UNIX users with an
    appropriately-configured restricted shell.  Relying on a '*' in the password
    field is not sufficient--that only means "deny logon", not "deny arbitrary
    shell command."
    
    For even tighter security, the shell can be reset to /bin/true , but that would
    not of course allow a user to call lp.
    
    OpenMail administrators can also look into the OpenMail "print server"
    functionality, particularly the documentation on the general.cfg setting
    UAL_PRINT_SERVER_ONLY in the OpenMail Technical Guide.
    
    
    Regards,
    
    richi.
    --
     Richi Jennings <richiat_private>        Phone: +44 (0)1344-365870 or HPT316-5870
     OpenMail Outbound & Technical        Pager: richi-beepat_private
     HP Communications Software Oper. UK  http://www.hp.com/go/openmail
    



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