I-065: SunOS ufsrestore Buffer Overflow Vulnerability

PROBLEM:       A buffer overflow vulnerability has been identified in the 
               ufsrestore utility, used to restore files from backup media 
               created with the ufsdump command. This is different from the 
               vulnerability identified in CIAC Bulletin I-049 and Sun 
               Security Bulletin #00169. 
PLATFORM:      Those running ufsrestore under Solaris 8, 7, 2.6, 2.5.1, and 
               2.5 (SunOS 5.8, 5.7, 5.6, 5.5.1, and 5.5), namely
               SunOS 5.8, 5.8_x86, 5.7, 5.7_x86, 5.6, 5.6_x86, 5.5.1, 
               5.5.1_x86, 5.5 and 5.5_x86. 
DAMAGE:        If exploited, this vulnerability allows local users to gain 
               root access. 
SOLUTION:      Apply either the workaround that was given in the original
               CIAC bulletin, or the patches given in the Sun bulletin. 
VULNERABILITY  The risk is HIGH.  Intruders have exploited this vulnerability 
ASSESSMENT:    to get root access after breaking into a user account. 
LINKS: 
 CIAC BULLETIN:      http://www.ciac.org/ciac/bulletins/i-065.shtml 
 ORIGINAL BULLETIN:  http://sunsolve.sun.com/pub-cgi
                             /retrieve.pl?doctype=coll&doc=secbull
                             /210&type=0&nav=sec.sba 

[Start of information taken from the original CIAC Bulletin]

SunOS ufsrestore Buffer Overflow Vulnerability

CIAC has learned that there is a new vulnerability in the ufsrestore utility 
in SunOS 5.5.1, 5.5.1_x86, 5.5 and 5.5_x86.  Note that this is not the same 
vulnerability described in CIAC Bulletin I-049 and Sun Security Bulletin 
#00169.  The new vulnerability is a buffer overflow vulnerability and is 
currently being exploited by intruders to get root access after breaking into 
a user account. 

System managers can use one of the following workarounds to protect their 
systems.

1. If you are not using the utilities or don't expect to use them very often, 
copy the files onto a floppy disk and delete them from your system. If you 
need the utilities, you can copy them back onto your system from the floppy.

The files remove are:
    /usr/lib/fs/ufs/ufsrestore
    /usr/lib/fs/ufs/ufsdump

The following files are links to the files in /usr/lib/fs/ufs and do not need 
to be changed.

    /usr/sbin/ufsrestore
    /usr/sbin/ufsdump

2. The second option is to change the permissions on the files so that only 
the root user can run them. Login as root and execute the following commands 
to change the permissions. Be sure the files are owned by root.

    chmod 500 /usr/lib/fs/ufs/ufsrestore
    chmod 500 /usr/lib/fs/ufs/ufsdump

If at some future date you need to change the permissions back to the original 
values, login as root and execute the following two commands. 

     chmod 4555 /usr/lib/fs/ufs/ufsrestore
     chmod 6555 /usr/lib/fs/ufs/ufsdump

[End of information taken from the original CIAC Bulletin]



[Start of Sun Microsystems Bulletin #210]


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________________________________________________________________________________
                    Sun Microsystems, Inc. Security Bulletin

Bulletin Number:          #00210
Date:                     October 23, 2001
Cross-Ref:                CERT Vulnerability Note VU#36866
Title:                    ufsrestore
________________________________________________________________________________

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.

IN NO EVENT WILL SUN MICROSYSTEMS, INC. BE LIABLE FOR ANY LOST REVENUE,
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.  Bulletins Topics

    Sun announces the release of patches for Solaris(tm) 8, 7, 2.6,
    2.5.1, and 2.5 (SunOS(tm) 5.8, 5.7, 5.6, 5.5.1, and 5.5) which
    relate to a vulnerability in ufsrestore(1M).

    Sun recommends that you install the patches listed in section 4
    immediately on systems running SunOS 5.8, 5.7, 5.6, 5.5.1, and
    5.5 which use ufsrestore.

2.  Who is Affected

    Vulnerable:                SunOS 5.8, 5.8_x86, 5.7, 5.7_x86, 5.6,
                               5.6_x86, 5.5.1, 5.5.1_x86, 5.5, 5.5_x86

    Not vulnerable:            Solaris 8 04/01*, Solaris 8 Maintenance
                               Update 4* and later update releases

*  To determine if one is running Solaris 8 04/01 or Solaris 8 Maintenance
   Update 4 or later, check the contents of the /etc/release file.

3.  Understanding the Vulnerability

    The ufsrestore utility restores files from backup media
    created with the ufsdump command.  A vulnerability has been
    found in ufsrestore which, if exploited, could allow an
    unprivileged local user to gain unauthorized root access.

    This issue was discovered by Job de Haas (job@itsx.com) of ITSX BV
    Amsterdam, The Netherlands (http://www.itsx.com).

    CERT Vulnerability Note VU#36866 is available from:

    http://www.kb.cert.org/vuls/id/36866

4.  List of Patches

    The following patches are available in relation to the above problem.

    OS Version               Patch ID
    __________               _________
    SunOS 5.8                109091-04 110387-02
    SunOS 5.8_x86            109092-04 110402-02
    SunOS 5.7                106793-07
    SunOS 5.7_x86            106794-07
    SunOS 5.6                105722-06
    SunOS 5.6_x86            105723-06
    SunOS 5.5.1              103640-35
    SunOS 5.5.1_x86          103641-35
    SunOS 5.5                103261-08
    SunOS 5.5_x86            103262-08
_______________________________________________________________________________
Sun acknowledges with thanks, Job de Haas (job@itsx.com) of ITSX BV
Amsterdam, The Netherlands (http://www.itsx.com), for bringing this issue
to our attention.
_______________________________________________________________________________

APPENDICES

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

    http://sunsolve.sun.com/securitypatch

B.  Checksums for the patches listed in this bulletin are available at:

    ftp://sunsolve.sun.com/pub/patches/CHECKSUMS

C.  Sun security bulletins are available at:

    http://sunsolve.sun.com/security

D.  Sun Security Coordination Team's PGP key is available at:

    http://sunsolve.sun.com/pgpkey.txt

E.  To report or inquire about a security problem with Sun software, contact
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        - Your local Sun answer centers
        - Your representative computer security response team, such as CERT
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    with a subject line (not body) containing one of the following commands:

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________________________________________________________________________________

Copyright 2001 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.

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[End of Sun Microsystems Bulletin #210]

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