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                                    CERT-Renater

                         Note d'Information No. 2006/VULN507
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DATE                      : 28/09/2006

HARDWARE PLATFORM(S)      : /

OPERATING SYSTEM(S)       : Solaris 10 running IPv6.

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Sun(sm) Alert Notification
      * Sun Alert ID: 102568
      * Synopsis: A Security Issue With Solaris 10 x64 Systems Using IPv6
        Forwarding May Result in a Denial of Service (DoS)
      * Category: Security
      * Product: Solaris 10 Operating System for x86 Platforms
      * BugIDs: 6222966
      * Avoidance: Patch, Workaround
      * State: Resolved
      * Date Released: 25-Sep-2006
      * Date Closed: 25-Sep-2006
      * Date Modified:

1. Impact

    Solaris 10 x64 systems configured to use Internet Protocol Version 6
    (ip6(7P)) may panic when processing certain IPv6 packets. A local or
    remote unprivileged user may be able to send IPv6 packets that could
    panic the system causing a Denial of Service (DoS).

2. Contributing Factors

    This issue can occur in the following releases:

    x86 Platform
      * Solaris 10 without patch 118855-16

    Note: Solaris 8 and Solaris 9, systems are not impacted by this issue.
    Solaris 10 sparc and Solaris 10 32 bit x86 systems are also not
    impacted.

    To determine if a system is running in 64-bit mode, the following
    command can be run:
     $ isainfo -b
     64

    If "64" is returned, the system is running in 64-bit mode.

    This issue only affects Systems that use IPv6 forwarding. To determine
    if a system is running with IPv6 enabled, the following command can be
    used:
     $ ifconfig -a6

    If entries are returned marked "UP and RUNNING" then the system is
    utilizing IPv6.

3. Symptoms

    If the described issue occurs, the system will panic with a stack
    trace similar to the following:
     fffffe80000b36c0 unix:die+da (ffffffff00000000, 184a16e00)
     fffffe80000b37a0 unix:trap+5ea ()
     fffffe80000b37b0 unix:cmntrap+11b ()
     fffffe80000b3980 ip:ip_rput_data_v6+e00 ()
     fffffe80000b39d0 ip:ip_rput_v6+193 ()
     fffffe80000b3a30 unix:putnext+1f1 ()
     fffffe80000b3b50 gld:gld_recv_tagged+21d ()
     fffffe80000b3b60 gld:ri_ste_def+333ebf2b ()

4. Relief/Workaround

    To work around the described issue, do not configure IPv6 addresses.
    To disable IPv6 on a system, run the following command as root:
     # ifconfig -a6 down

    Edit the "/etc/nsswitch.conf" file and change the "ipnodes" entry to
    be "files" only. IPv6 will function again after a reboot.

    Note: To disable IPv6 on systems across a system reboot, the
    "/etc/hostname6.<interface>" files can be temporarily renamed.

    Alternatively, to workaround the described issue while maintaining
    IPv6 functionality, boot the system in 32-bit mode.

    To specify the 32-bit kernel, as root or with equivalent privileges,
    enter the following command:
     # eeprom boot-file=kernel/unix

    Upon the next reboot, the system will be running the 32-bit kernel.

    Once the patch for this issue is installed, to reinstate 64 bit mode,
    as root or with equivalent privileges, enter the following command:
     # eeprom boot-file=kernel/amd64/unix

    Upon the next reboot, the system will be running the 64-bit kernel.

5. Resolution

    This issue is addressed in the following releases:

    x86 Platform
      * Solaris 10 with patch 118855-16 or later

    This Sun Alert notification is being provided to you on an "AS IS"
    basis. This Sun Alert notification may contain information provided by
    third parties. The issues described in this Sun Alert notification may
    or may not impact your system(s). Sun makes no representations,
    warranties, or guarantees as to the information contained herein. ANY
    AND ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION
    WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
    NON-INFRINGEMENT, ARE HEREBY DISCLAIMED. BY ACCESSING THIS DOCUMENT
    YOU ACKNOWLEDGE THAT SUN SHALL IN NO EVENT BE LIABLE FOR ANY DIRECT,
    INDIRECT, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES THAT ARISE
    OUT OF YOUR USE OR FAILURE TO USE THE INFORMATION CONTAINED HEREIN.
    This Sun Alert notification contains Sun proprietary and confidential
    information. It is being provided to you pursuant to the provisions of
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    such an agreement, the Sun.com Terms of Use. This Sun Alert
    notification may only be used for the purposes contemplated by these
    agreements.

    Copyright 2000-2006 Sun Microsystems, Inc., 4150 Network Circle, Santa
    Clara, CA 95054 U.S.A. All rights reserved

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