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                        The U.S. Department of Energy
                    Computer Incident Advisory Capability
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                              INFORMATION BULLETIN

              SunOS/Solbourne loadmodule and modload Vulnerability

December 15, 1993 1200 PST                                         Number E-05
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PROBLEM:   Security vulnerability in loadmodule and modload.
PLATFORM:  OpenWindows 3.0 under SunOS 4.1.x on sun4 and Solbourne systems.
DAMAGE:    Local users may gain root level access to the system.
SOLUTION:  Apply patches to SunOS systems or implement workaround on Solbourne
           machines.
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     Critical Information about the loadmodule and modload Vulnerability

CIAC has received information from Sun Microsystems and Solbourne regarding a
security vulnerability in the /usr/etc/modload and $OPENWINHOME/bin/loadmodule
utilities that allows local users to execute commands as root.  This
vulnerability affects systems with OpenWindows 3.0 installed under SunOS 4.1.x
on sun4 and Solbourne architectures.  It does not affect Solaris 2.x systems,
sun3 architectures, or other versions of OpenWindows.

Sun Microsystems has released patched versions of the loadmodule and modload
utilities:

                                                   /bin/sum
           Utility     Patch ID   Filename         Checksum
           ----------  ---------  ---------------  --------
           loadmodule  100448-02  100448-02.tar.Z  19410  5
           modload     101200-02  101200-02.tar.Z  41677 28

Individuals with Sun support contracts may obtain these patches from their
local Sun Answer Center or from SunSolve Online.  Security patches are also
available without a support contract via anonymous FTP from ftp.uu.net 
(IP 192.48.96.9) in the directory /systems/sun/sun-dist.

Solbourne systems do not make use of the loadmodule utility.  On these
systems, the vulnerability may be removed by turning off the file's setuid
bit by executing the following command as root:

           chmod 0755 /usr/openwin/bin/loadmodule

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CIAC wishes to thank Sun Microsystems and Solbourne for their response to this
problem.
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For additional information or assistance, please contact CIAC:
    Voice:   (510) 422-8193
    FAX:     (510) 423-8002
    STU-III: (510) 423-2604
    E-mail:  ciac@llnl.gov

Previous CIAC Bulletins and other information are available via anonymous FTP
from irbis.llnl.gov (IP address 128.115.19.60).
______________________________________________________________________________

PLEASE NOTE: Many users outside of the DOE and ESnet computing communities
receive CIAC bulletins.  If you are not part of these communities, please
contact your agency's response team to report incidents.  Your agency's team
will coordinate with CIAC.  The Forum of Incident Response and Security Teams
(FIRST) is a world-wide organization.  A list of FIRST member organizations
and their constituencies can be obtained by sending email to
docserver@first.org with an empty subject line and a message body containing
the line: send first-contacts.

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