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CA-94:04                         CERT Advisory
                                March 17,  1994
                       SunOS /usr/ucb/rdist Vulnerability

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The CERT Coordination Center has received information concerning a
vulnerability in /usr/ucb/rdist in Sun Microsystems, Inc. SunOS 4.1.1,
4.1.2, 4.1.3, and 4.1.3c on all sun3 and sun4 architectures.  SunOS 4.1.3_U1,
Solaris 2.x, and Solbourne's 4.1B and 4.1C are not vulnerable.

This is a Sun specific Advisory.  Please reference CERT Advisory CA-91:20
"/usr/ucb/rdist Vulnerability" for general information regarding other
vendors.  A vendor status file pub/cert_advisories/rdist-patch-status is
available via anonymous FTP from info.cert.org.

This vulnerability is being actively exploited; please review CERT Advisory
CA-94:01 "Ongoing Network Monitoring Attacks."

Patches can be obtained from local Sun Answer Centers worldwide as well as
through anonymous FTP from ftp.uu.net in the /systems/sun/sun-dist directory.
In Europe, these patches are available from ftp.eu.net in the
/sun/fixes directory.

Information concerning specific patches is outlined below. Please note
that Sun sometimes updates patch files.  If you find that the checksum
is different, please contact Sun.

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I.   Description

     A security vulnerability exists in /usr/ucb/rdist that
     can be used to gain unauthorized privileges.  Under some
     circumstances /usr/ucb/rdist can be used to create setuid
     root programs.

II.  Impact

     This vulnerability allows a local user to gain root access.

III. Solution

     A.  If rdist is not being used, change the permissions on the file.

         # chmod 700 /usr/ucb/rdist

     B.  Obtain and install the appropriate patches according to the
         instructions included with the patches.

         Module           Patch ID        Filename
         ----------       ---------       ---------------
         rdist            100383-06       100383-06.tar.Z

                BSD Checksum = 58984 121
		System V Checksum = 9125 241
		MD5 Checksum = f8f78ddab19af5efabb9bd66fc8f5c1a

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If you believe that your system has been compromised, contact the CERT
Coordination Center or your representative in Forum of Incident
Response and Security Teams (FIRST).

Internet E-mail: cert@cert.org
Telephone: 412-268-7090 (24-hour hotline)
           CERT personnel answer 8:30 a.m.-5:00 p.m. EST(GMT-5)/EDT(GMT-4),
           and are on call for emergencies during other hours.

CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh, PA 15213-3890

Past advisories, information about FIRST representatives, and other
information related to computer security are available for anonymous
FTP from info.cert.org.