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CERT Coordination Center


Sun Solaris catman creates temporary files insecurely

Vulnerability Note VU#115112

Original Release Date: 2001-09-27 | Last Revised: 2001-09-27

Overview

catman, the unix manual display utility, creates insecure temporary files with predictable names in a world-writable directory. Since catman executes with system administration privileges, a symbolic link attack could overwrite arbitrary files.

Description

There is a vulnerability in catman that allows attackers to overwrite arbitrary files, regardless of ownership. The catman program creates temporary files with predictable names and paths such as /tmp/sman_pidofcatman. By monitoring the process ids (PID) of currently running processes, attackers can predict the next PID to be assigned, which will allow them to predict the filename. Once the filename is established, the attacker then creates a symbolic link from the temporary file to the file they want to overwrite. Because the catman program runs as root, it is able to overwrite the file targeted by the symbolic link.

Impact

Attackers can exploit the predictability of catman temporary filenames to overwrite arbitrary system files, regardless of ownership.

Solution

The CERT/CC is currently unaware of a practical solution to this problem.

Vendor Information

115112
Expand all

Sun

Notified:  January 30, 2001 Updated:  September 26, 2001

Status

  Vulnerable

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.

Addendum

________________________________________________________________________________
  Sun Microsystems, Inc. Security Bulletin

Bulletin Number:#00184
Date: February 10, 1999
Cross-Ref:
Title:man/catman
________________________________________________________________________________

The information contained in this Security Bulletin is provided "AS IS."
Sun makes no warranties of any kind whatsoever with respect to the information
contained in this Security Bulletin. ALL EXPRESS OR IMPLIED CONDITIONS,
REPRESENTATIONS AND WARRANTIES, INCLUDING ANY WARRANTY OF NON-INFRINGEMENT OR
IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE
HEREBY DISCLAIMED AND EXCLUDED TO THE EXTENT ALLOWED BY APPLICABLE LAW.

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PROFIT OR DATA, OR FOR DIRECT, SPECIAL, INDIRECT, CONSEQUENTIAL, INCIDENTAL
OR PUNITIVE DAMAGES HOWEVER CAUSED AND REGARDLESS OF ANY THEORY OF LIABILITY
ARISING OUT OF THE USE OF OR INABILITY TO USE THE INFORMATION CONTAINED IN
THIS SECURITY BULLETIN, EVEN IF SUN MICROSYSTEMS, INC. HAS BEEN ADVISED OF
THE POSSIBILITY OF SUCH DAMAGES.

If any of the above provisions are held to be in violation of applicable law,
void, or unenforceable in any jurisdiction, then such provisions are waived
to the extent necessary for this disclaimer to be otherwise enforceable in
such jurisdiction.
________________________________________________________________________________

1.  Background

    The man command displays information from the reference manuals. The
   catman utility creates preformatted versions of the on-line manuals.
   Vulnerabilities have been discovered with these commands that may be
   exploited to overwrite arbitrary files when man or catman is executed
   by root.

2.  Affected Supported Versions

    Solaris(tm) versions:   7, 7_x86, 2.6, 2.6_x86, 2.5.1, 2.5.1_x86, 2.5,
                           2.5_x86, 2.4, 2.4_x86, and 2.3

    SunOS(tm) versions:     4.1.4 and 4.1.3_U1

3.  Recommendations

    Sun recommends that you install the respective patches immediately
   on affected systems.

    Operating SystemPatch ID
   _________________   _________
   Solaris 7           107038-01
   Solaris 7_x86       107039-01
   Solaris 2.6         106123-04
   Solaris 2.6_x86     106124-04
   Solaris 2.5.1       106905-01
   Solaris 2.5.1_x86   106906-01
   Solaris 2.5         106907-01
   Solaris 2.5_x86     106908-01
   Solaris 2.4         106912-01
   Solaris 2.4_x86     106962-01
   Solaris 2.3         106911-01
   SunOS   4.1.4107157-01
                       107144-01
   SunOS   4.1.3_U1107156-01
                       107143-01

_______________________________________________________________________________
APPENDICES

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

    <URL:http://sunsolve.sun.com/sunsolve/pubpatches/patches.html>

B.  Checksums for the patches listed in this bulletin are available via
   World Wide Web at:

    <URL:http://sunsolve.sun.com/sunsolve/pubpatches/patches.html>

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

<URL:http://sunsolve.sun.com/sunsolve/secbulletins>

D.  Sun Security Coordination Team's PGP key is available via World Wide Web
   at:

<URL:http://sunsolve.sun.com/sunsolve/secbulletins/SunSCkey.txt>

E.  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

F.  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
       _______         _________________________________

        help            An explanation of how to get information

        key             Sun Security Coordination Team's PGP key

        list            A list of current security topics

        query [topic]   The email is treated as an inquiry and is forwarded to
                       the Security Coordination Team

        report [topic]  The email is treated as a security report and is
                       forwarded to the Security Coordination Team. Please
                       encrypt sensitive mail using Sun Security Coordination
                       Team's PGP key

        send topic      A short status summary or bulletin. For example, to
                       retrieve a Security Bulletin #00138, supply the
                       following in the subject line (not body):

                                send #138

        subscribe       Sender is added to our mailing list.  To subscribe,
                       supply the following in the subject line (not body):

                            subscribe cws your-email-address

                        Note that your-email-address should be substituted
                       by your email address.

        unsubscribe     Sender is removed from the CWS mailing list.
________________________________________________________________________________

Copyright 1999 Sun Microsystems, Inc. All rights reserved. Sun,
Sun Microsystems, Solaris and SunOS are trademarks or registered trademarks
of Sun Microsystems, Inc. in the United States and other countries. This
Security Bulletin may be reproduced and distributed, provided that this
Security Bulletin is not modified in any way and is attributed to
Sun Microsystems, Inc. and provided that such reproduction and distribution
is performed for non-commercial purposes.

If you have feedback, comments, or additional information about this vulnerability, please send us email.


CVSS Metrics

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A

References

Credit

This vulnerability was first described by Larry W. Cashdollar.

This document was last modified by Tim Shimeall.

Other Information

CVE IDs: CVE-2001-0095
Severity Metric: 12.60
Date Public: 2001-01-30
Date First Published: 2001-09-27
Date Last Updated: 2001-09-27 18:23 UTC
Document Revision: 13

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