Dear SCO Customer,

Support Level Supplement (SLS) PTF3383B, the SCO Evaluation Security 
Supplement, contains the following changes needed for the SCO UnixWare 
Release 2.1.0 C2 evaluation:

     1. CERT (Computer Emergency Response Team) identified a vulnerability
        in the at(1) utility in CERT advisory CA-97.18 (12 June 1997). The
        new at(1) utility provided in this SLS addresses this vulnerability.
        The CERT advisory is available from :

             ftp://info.cert.org/pub/cert_advisories/CA-97.18.at

     2. A revised version of the 'scheme' binary is included. This version 
        of 'scheme' addresses a problem with the DISABLETIME parameter that 
        is configurable with defadm(1M) login.

     3. Revised versions of certain auditing utilities, and the kernel 
        auditing driver are included to fix problems with the IPC_R constant 
        multiply defined.

     4. A new version of the vtlmgr is included to close security problems 
        with the /dev/vt* devices.

     5. Revised svc drivers are included to address an auditing problem where
        failed adjtime(2) calls were being audited as completing successfully.

     6. New tfadmin, adminrole and adminuser utilities are included that 
        validate the login id of the user.

     7. A new priocntl is included that closes security flaws.

     8. A new libXt library is included to close various vulnerabilities in 
        this library as reported by CERT.


Software Notes and Recommendations
----------------------------------

SLS PTF3383B should only be installed on:

        SCO UnixWare Application Server 2.1.0 
        SCO UnixWare Personal Edition 2.1.0

Testing of the modified software contained in this SLS has been
conducted only to the extent necessary to confirm that it resolves
the problems stated above. Such testing consists of re-creating the
problem conditions (typically in a SCO test laboratory) and verifying
that the problem no longer occurs.  No other testing of this software
has been done.


Hardware Notes and Recommendations
----------------------------------

This SLS package is targeted for the i386, i486 and Pentium CPUs.


Installation Instructions
-------------------------

1. Download the ptf3383b.Z and ptf3383b.txt files to the /tmp directory
   on your machine.

2. As root, uncompress the file and add the SLS package to your
   system using these commands:

       $ su
       Password: <type your root password>
       # uncompress /tmp/ptf3383b.Z
       # pkgadd -d /tmp/ptf3383b

3. Reboot the system after installing this SLS.  A new unix kernel
   will be built and the system will then reboot itself.

   A system reboot is required following installation of this SLS in 
   order for the changes to take effect.


Removal Instructions
---------------------

1. As root, remove the SLS package.

   $ su
   # pkgrm ptf3383

2. Reboot the system after removing this SLS.


If you have any questions regarding this SLS, or the product on which 
it is installed, please contact your software supplier.