Sun Security Bulletin #00139

[secure () SUNSC ENG SUN COM (Sun Security Coordination Team)]

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         SUN MICROSYSTEMS SECURITY BULLETIN: #00139, 29 APRIL 1997
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BULLETIN TOPICS

Sun announces the release of patches for Solaris 2.5.1 (SunOS 5.5.1) and
Solaris 2.5 (SunOS 5.5) that relate to vulnerabilities in the pluggable
authentication module (PAM), which can result in root access if exploited.
The nispasswd, yppasswd, and passwd programs use PAM in these OS releases.

Sun estimates that the release of patches for Solaris 2.4 (SunOS 5.4) and
Solaris 2.3 (SunOS 5.3) that relate to the same vulnerability will be
available within 5 weeks and 6 weeks respectively of the date of this bulletin.
In Solaris 2.4 and 2.3, the passwd programs use unix_scheme instead of PAM.

Sun strongly recommends that you install these patches immediately on
every affected system. Exploit information is publicly available.


I.   Who is Affected, and What to Do

II.  Understanding the Vulnerabilities

III. List of Patches

IV.  Checksum Table


APPENDICES

A.   How to obtain Sun security patches

B.   How to report or inquire about Sun security problems

C.   How to obtain Sun security bulletins or short status updates


Sun acknowledges with thanks the CERT Coordination Center (Carnegie
Mellon University) and AUSCERT for their assistance in the preparation of
this bulletin.

Sun, CERT/CC, and AUSCERT are members of FIRST, the Forum of Incident
Response and Security Teams. For more information about FIRST, visit
the FIRST web site at "http://www.first.org/";.

Cross-Ref:      AUSCERT AA-97.09

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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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         SUN MICROSYSTEMS SECURITY BULLETIN: #00139, 29 APRIL 1997
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I.   Who is Affected, and What to Do

     SunOS versions 5.5.1, 5.5.1_x86, 5.5, 5.5_x86, 5.4, 5.4_x86, and 5.3
     are vulnerable.
     SunOS versions 4.1.4 and 4.1.3_U1 are not vulnerable.

     Install the patches listed in III. for SunOS versions 5.5.1, 5.5.1_x86,
     5.5, and 5.5_x86.

     Sun estimates that patches for SunOS versions 5.4 and 5.4_x86 will
     be released within 5 weeks from the date of this bulletin. Sun also
     estimates that patches for SunOS version 5.3 will be released within 6
     weeks from the date of this bulletin. In the meantime, Sun recommends, as
     a workaround, the installation of a passwd wrapper that was developed by
     AUSCERT (see AUSCERT Advisory AA-97.09). AUSCERT maintains an anonymous
     FTP service at ftp://ftp.auscert.org.au/pub/ and a World Wide Web service
     at http://www.auscert.org.au/.

     The same vulnerability has been fixed in the upcoming release of Solaris.


II.  Understanding the Vulnerability

Due to insufficient bounds checking on arguments in PAM (5.5.1 and 5.5) and
unix_scheme (5.4 and 5.3), it is possible to overwrite the internal stack space
of the passwd program. If exploited, this vulnerability can be used to gain
root access on attacked systems.

Under SunOS 5.5.1 and 5.5, yppasswd and nispasswd are hard links to the passwd
program and therefore are also vulnerable. Under SunOS 5.4 and 5.3, passwd,
yppasswd, and nispasswd are separate programs but they dynamically link
unix_scheme and are affected.


III. List of Patches

The vulnerabilities relating to passwd in PAM and unix_scheme are fixed by
the following patches:

        OS version              Patch ID
        ----------              --------

        SunOS 5.5.1             104433-03
        SunOS 5.5.1_x86         104434-02
        SunOS 5.5               103178-03
        SunOS 5.5_x86           103179-03
        SunOS 5.4               101945-49       (to be released in 5 weeks)
        SunOS 5.4_x86           101946-43       (to be released in 5 weeks)
        SunOS 5.3               101318-87       (to be released in 6 weeks)


IV.  Checksum Table

In the table below, we show the BSD checksums (SunOS 4.1.x: /bin/sum;
SunOS 5.x: /usr/ucb/sum), SVR4 checksums (SunOS 5.x: /usr/bin/sum), and the
MD5 digital signatures for the compressed tar files.

File              BSD          SVR4          MD5
Name              Checksum     Checksum      Digital Signature
---------------   ---------    ---------     --------------------------------
104433-03.tar.Z   38148 225    11004 449     80C625D86DBFA06C107956EB4BD8126A
104434-02.tar.Z   22283 142    51656 284     4079E48BB8BA929F99EFE4D38877B023
103178-03.tar.Z   11476 212    51066 423     74547F3FDF850FAAF6B02176CF146AA4
103179-03.tar.Z   55629 192    1250 384      CA11D05845116F62FCC8DDCC6EDBCB2B


APPENDICES

A.   How to obtain Sun security patches

    1. If you have a support contract

    Customers with Sun support contracts can obtain any patches listed
    in this bulletin (and any other patches--and a list of patches) from:

       - SunSolve Online
       - Local Sun answer centers, worldwide
       - SunSITEs worldwide

    The patches are available via World Wide Web at http://sunsolve.sun.com.

    You should also contact your answer center if you have a support
    contract and:

       - You need assistance in installing a patch
       - You need additional patches
       - You want an existing patch ported to another platform
       - You believe you have encountered a bug in a Sun patch
       - You want to know if a patch exists, or when one will be ready

    2. If you do not have a support contract

    Customers without support contracts may now obtain security patches,
    "recommended" patches, and patch lists via SunSolve Online.

    Sun does not furnish patches to any external distribution sites
    other than the ones mentioned here. The ftp.uu.net and ftp.eu.net
    sites are no longer supported.

    3. About the checksums

    So that you can quickly verify the integrity of the patch files
    themselves, we supply in each bulletin checksums for the tar archives.

    Occasionally, you may find that the listed checksums do not match
    the patches on the SunSolve or SunSite database. This does not
    necessarily mean that the patch has been tampered with. More likely,
    a non-substantive change (such as a revision to the README file)
    has altered the checksum of the tar file. The SunSolve patch database
    is refreshed nightly, and will sometimes contain versions of a patch
    newer than the one on which the checksums were based.

    In the future we may provide checksum information for the
    individual components of a patch as well as the compressed archive
    file. This would allow customers to determine, if need be, which
    file(s) have been changed since we issued the bulletin containing
    the checksums.

    In the meantime, if you would like assistance in verifying the
    integrity of a patch file please contact this office or your local
    answer center.


B.   How to report or inquire about Sun security problems

If you discover a security problem with Sun software or wish to
inquire about a possible problem, contact one or more of the
following:

   - Your local Sun answer centers
   - Your representative computer security response team, such as CERT
   - This office. Address postal mail to:

         Sun Security Coordinator
         MS MPK17-103
         2550 Garcia Avenue
         Mountain View, CA 94043-1100

         Email: security-alert () sun com

We strongly recommend that you report problems to your local Answer
Center. In some cases they will accept a report of a security bug
even if you do not have a support contract. An additional notification
to the security-alert alias is suggested but should not be used as your
primary vehicle for reporting a bug.


C.   How to obtain Sun security bulletins or short status updates

    1. Subscription information

    Sun Security Bulletins are available free of charge as part of
    our Customer Warning System. It is not necessary to have a Sun
    support contract in order to receive them.

    To receive information or to subscribe or unsubscribe from our
    mailing list, send mail to security-alert () sun com with a subject
    line containing one of the following commands.


        Subject         Information Returned/Action Taken
        -------         ---------------------------------

        HELP            An explanation of how to get information

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        QUERY [topic]   The mail containing the question is relayed to
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        REPORT [topic]  The mail containing the text is treated as a
                        security bug report and forwarded to a Security
                        Coordinator for handling. Please note that this
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                        purpose.  Note also that we do not recommend
                        that detailed problem descriptions be sent in
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        SEND topic      Summary of the status of selected topic. (To
                        retrieve a Sun Security Bulletin, supply the
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        SUBSCRIBE       Sender is added to the CWS (Customer
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                                SUBSCRIBE cws your-email-address

        UNSUBSCRIBE     Sender is removed from the CWS list.


    Should your email not fit into one of the above subjects, a help
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    Due to the volume of subscription requests we receive, we cannot
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    you wish to verify that your subscription request was received, or
    if you would like your bulletin delivered via postal mail or fax.

    2. Obtaining old bulletins

    Sun Security Bulletins are available via the security-alert alias
    and on SunSolve. Please try these sources first before contacting
    this office for old bulletins.

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