Sun Security Bulletin #00144

Aleph One (aleph1@DFW.NET)
Tue, 24 Jun 1997 15:37:48 -0500

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Sun Microsystems, Inc. Security Bulletin

Bulletin Number: #00144
Date: June 24 1997
Cross-Ref: AUSCERT AA 97.18
Title: Vulnerability in chkey

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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, and 2.4,
(SunOS 5.5.1, 5.5, and 5.4), that relate to a vulnerability in the
chkey program.

Sun estimates that the release of a patch for Solaris 2.3 (SunOS 5.3) that
relate to the same vulnerability will be available within 16 weeks of the
date of this bulletin.

Sun strongly recommends that you install the patches listed in section 4
immediately on systems running SunOS 5.5.1, 5.5, and 5.4. Sun also strongly
recommends that you install the workaround listed in section 5 immediately
on systems running SunOS 5.3. Exploit information for chkey is publicly
available.

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

The vulnerability is fixed in the upcoming release of Solaris.

3. Understanding the Vulnerability

The program chkey is used to change a user's secure RPC Diffie-Hellman
public key and secret key pair. Due to insufficient bounds checking on
arguments passed to the chkey program, it is possible to overwrite the
internal data space of chkey while it is executing. As chkey has setuid
root permissions, this vulnerability may allow non-privileged users to
gain root access.

4. Workaround

Sun recommends, as a workaround, the installation of a wrapper that was
developed by AUSCERT (see AUSCERT Advisory AA-97.18). AUSCERT maintains an
FTP service at ftp://ftp/auscert/org.au/pub and a World Wide Web service
at http://www.auscert.org.au.

5. List of Patches

The vulnerability in chkey is fixed by the following patches:

OS version Patch ID
---------- --------
SunOS 5.5.1 104968-01
SunOS 5.5.1_x86 104969-01
SunOS 5.5 104971-01
SunOS 5.5_x86 104972-01
SunOS 5.4 104973-01
SunOS 5.4_x86 104974-01
SunOS 5.3 101318-89 (to be released in 16 weeks)

6. 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:

ftp://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
- --------------- --------- --------- --------------------------------
104968-01.tar.Z 42439 112 58380 224 D468EDAF62453686D9744601BC69B52B
104969-01.tar.Z 29618 112 5311 224 4C6F5D9D18A38BD8B54B76B8137F63BD
104971-01.tar.Z 31970 112 5776 223 34AD0B220C2495B73DBC621D88CF988B
104972-01.tar.Z 49195 112 35168 224 D6CF025F259437335625EF325196F51D
104973-01.tar.Z 64330 115 23425 230 D50F404FC7DB918DB556F38F7DBF8816
104974-01.tar.Z 54484 112 33221 223 42B484654CD4C7F8EB7A9B54BC9061FB

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Sun acknowledges with thanks AUSCERT for their assistance in the preparation
of this bulletin.

Sun 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/".
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APPENDICES

A. Patches listed in this bulletin are available to all Sun customers via
World Wide Web at:

ftp://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. Sun security bulletins are available via World Wide Web at:

http://sunsolve1.sun.com/sunsolve/secbulletins

C. 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

D. To receive information or subscribe to our CWS (Customer Warning System)
mailing list, send email to:

security-alert@sun.com

with a subject line (not body) containing one of the following commands:

Command Information Returned/Action Taken
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