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                   Sun Microsystems, Inc. Security Bulletin

                

Bulletin Number:        #00142

Date:                   June 4 1997

Cross-Ref:              

Title:                  Vulnerability in rpcbind



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Permission is granted for the redistribution of this Bulletin, so long as 

the Bulletin is not edited and is attributed to Sun Microsystems. Portions 

may also be excerpted for re-use in other security advisories so long as 

proper attribution is included.



Any other use of this information without the express written consent of 

Sun Microsystems is prohibited. Sun Microsystems expressly disclaims all 

liability for any misuse of this information by any third party.

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1.  Bulletins Topics



    Sun announces the release of patches for Solaris 2.5.1, 2.5, 2.4, and 2.3

    (SunOS 5.5.1, 5.5, 5.4, and 5.3), that relate to a vulnerability in the

    rpcbind program, which can aid an attacker to gain unauthorized access if

    exploited.

    

    Sun strongly recommends that you install the patches listed in section 4 

    immediately on every affected system.

    

2.  Who is Affected

        

       Vulnerable:      SunOS versions 5.5.1, 5.5.1_x86, 5.5, 5.5_x86, 

                                       5.4, 5.4_x86, and 5.3.

      

       Not vulnerable:  All other supported versions of SunOS

                 

       This vulnerability is fixed in the upcoming release of Solaris.

     

3.  Understanding the Vulnerability



    The rpcbind program is a server that converts RPC program numbers into

    universal addresses. When an RPC service is started, it tells rpcbind the 

    address at which it is listening, and the RPC program numbers it is 

    prepared to serve. When a client wishes to make an RPC call to a given 

    program number, it first contacts rpcbind on the server machine to 

    determine the address where RPC requests should be sent.

    

    Under Solaris 2.x, rpcbind listens not only on TCP port 111 and UDP port

    111, but also on a UDP port number greater than 32770. The exact number 

    depends on the OS release and architecture. This results in a large number 

    of packet filters which intend to block access to rpcbind/portmapper being 

    ineffective. Instead of sending requests to TCP or UDP port 111, the 

    attacker simply sends them to the other UDP port. This vulnerability allows 

    an attacker to obtain remote RPC program information even if TCP or UDP 

    port 111 is being filtered. It can also aid an attacker to gain 

    unauthorized access to hosts running vulnerable versions of the software.

        

4.  List of Patches



    The vulnerability relating to rpcbind is fixed by the following patches:



        OS version              Patch ID

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

        SunOS 5.5.1             104331-02

        SunOS 5.5.1_x86         104332-02

        SunOS 5.5               104357-02

        SunOS 5.5_x86           104358-02

        SunOS 5.4               102070-03       

        SunOS 5.4_x86           102071-03       

        SunOS 5.3               102034-02       



5.  Checksum Table



    The checksum table below shows the BSD checksums (SunOS 5.x: /usr/ucb/sum),

    SVR4 checksums (SunOS 5.x: /usr/bin/sum), and the MD5 digital signatures 

    for the above-mentioned patches that are available from:

     

        http://sunsolve1.sun.com/pub/patches/patches.html

        

    These checksums may not apply if you obtain patches from your answer

    centers. 



File Name         BSD         SVR4         MD5

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

104331-02.tar.Z   64512 111   17253 222    29C2D5649C56A3D64E1F1DFCE3783842

104332-02.tar.Z   56808 111   23404 221    4B5D28F4A686166C4C147BE4E9563B8C

104357-02.tar.Z   27488 111   31772 222    316B03F737FC61DC09877C2BB822E7EE

104358-02.tar.Z   22598 110   46888 220    1665E8724D0A3DB401A00BE812630A37

102070-03.tar.Z   32763 100   14089 200    31FB11BC9D89A6D540F87624D4A2CFAE

102071-03.tar.Z   21217 100   18859 199    76DDAF2CAE25535A9AE932F3B0C98E3A

102034-02.tar.Z   23648 100   49973 199    243CD25673D87D0277F5CFE06E327347



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Sun acknowledges with thanks Secure Networks, Inc. for their assistance in the 

preparation of this bulletin.

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APPENDICES



A.  Patches listed in this bulletin are available to all Sun customers via 

    World Wide Web at:

    

        http://sunsolve1.sun.com/pub/patches/patches.html

        

    Customers with Sun support contracts can also obtain patches from local 

    Sun answer centers and SunSITEs worldwide.



B.  To report or inquire about a security problem with Sun software, contact 

    one or more of the following:

  

        - Your local Sun answer centers

        - Your representative computer security response team, such as CERT 

        - Sun Security Coordination Team. Send email to:

         

                security-alert@sun.com



C.  To receive information or subscribe to our CWS (Customer Warning System) 

    mailing list, send email to:

    

                security-alert@sun.com

   

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