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SCO Security Bulletin 96:002

September 4, 1996

Patch for system call security issue

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The Santa Cruz Operation has discovered the following problem present in

our software:



I.   Description



     A problem in a particular system call may allow unauthorized

     access to the system. The resulting access may lead to unauthorized

     root access to the system.



II.  Impact



     Any user with an account on the system may be able to gain

     unauthorized access to system or user files, which may then lead to

     unauthorized root access.



III. Releases



     This problem exists on the following releases of SCO products:



        SCO(R) UnixWare(R) release 2.0.x and 2.1.0



IV. Solution



     SCO is providing Program Temporary Fix (PTF) 3063 to address the

     issue. This PTF is available for SCO UnixWare release 2.1.0. SCO intends

     to release a PTF for SCO UnixWare release 2.0.3 in the near future.



     A workaround for users of SCO UnixWare release 2.0.x or for those

     who are not yet able to install this PTF follows:



     As root, execute these commands on the system console:



        # /etc/conf/bin/idtune -f RSTCHOWN 1

        # /etc/conf/bin/idbuild -B

        # init 6



     This procedure sets a kernel parameter that prevents the problem from

     occuring, relinks the kernel, and reboots the system.



You can download the PTF as follows:



Anonymous ftp   (World Wide Web URL)

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        http://ftp.sco.COM/UW21/ptf3063.Z     (patch image, compressed)

        http://ftp.sco.COM/UW21/ptf3063.txt   (cover letter/installation notes)



Compuserve

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PTF 3063 is also available in the UNIXWARE forum on Compuserve.





SCO Online Support (SOS) BBS

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PTF 3063 can also be downloaded interactively via X, Y, or Z MODEM or Kermit,

using the SCO Online Support System (SOS). Follow the menus selections under

"Toolchest" from the main SOS menu.



The phone numbers available for interactive transfer from SOS are:



1-408-426-9495                  (USA)

+44 (0)1923 210 888             (United Kingdom)



Checksums

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MD5

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MD5 (ptf3063.Z) = 1093420123c9bff603bd3c32a3867dcd

MD5 (ptf3063.txt) = 0ffa24e5e0d9a8caf8f4076149d782c3



sum -r (on UnixWare)

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48571   391 ptf3063.Z

20546     3 ptf3063.txt



This bulletin is available for anonymous ftp download from

http://ftp.sco.COM/SSE/security_bulletins/SB.96:02a, and will be updated

as new information becomes available.



If you have further questions, contact your support provider.  If you

need to contact SCO, please send electronic mail to support@sco.COM, or

contact SCO as follows.



        USA/Canada: 6am-5pm Pacific Daylight Time (PDT)

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        1-800-347-4381  (voice)

        1-408-427-5443  (fax)



        Pacific Rim, Asia, and Latin American customers: 6am-5pm Pacific

        ------------------------------------------------ Daylight Time

                                                         (PDT)

        1-408-425-4726  (voice)

        1-408-427-5443  (fax)



        Europe, Middle East, Africa: 9am-5:30pm Greenwich Mean Time (GMT)

        ----------------------------

        +44 (0)1923 816344 (voice)

        +44 (0)1923 817781 (fax)