CERT Advisory - Revised Patch for SunOS rpc.mountd Vulnerability

Mon Feb 14 21:37:45 UTC 1994

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CA-94:02                        CERT Advisory
                              February 14, 1994
            Revised Patch for SunOS /usr/etc/rpc.mountd Vulnerability

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                    *** THIS IS A REVISED CERT ADVISORY ***
           *** IT CONTAINS NEW VULNERABILITY AND PATCH INFORMATION ***
             *** SUPERSEDES CERT ADVISORY CA-91:09 and CA-92:12 ***

The CERT Coordination Center has received information concerning a
vulnerability in /usr/etc/rpc.mountd in Sun Microsystems, Inc. SunOS
4.1.1, 4.1.2, 4.1.3, and 4.1.3c.  SunOS 4.1.3.u.1, Solaris 2.x, and
Solbourne's 4.1B and 4.1C are not vulnerable.

Sun has produced a patch for this vulnerability for sun3 and sun4
architectures.  It is available through your local Sun Answer Center
as well as through anonymous FTP from the ftp.uu.net system in the
/systems/sun/sun-dist directory or from the ftp.eu.net system in the
/sun/fixes directory.

This vulnerability is currently being exploited.  Please review CERT 
Advisory CA-94:01 'Ongoing Network Monitoring Attacks'.

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I.   Description

     If an access list of hosts within /etc/exports is a string 
     over 256 characters or if the cached list of netgroups exceeds
     the cache capacity then the filesystem can be mounted by anyone.

II.  Impact

     Unauthorized remote hosts will be able to mount the filesystem.
     This will allow unauthorized users read and write access to files
     on mounted filesystem.

III. Solution

     Obtain and install the appropriate patch following the instructions
     included with the patch.

     Patch-ID   Filename         BSD        MD5
                                 Checksum   Checksum
     100296-04  100296-04.tar.Z  42492 40   20a76c75abadd3360ad92091a25ceb3c

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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 at 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.