IRIX /dev/ipfilter Denial of Service vulnerability

[SGI Security Coordinator <agent99 () sgi com>]

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_____________________________________________________________________________

                          SGI Security Advisory

        Title:      /dev/ipfilter Denial of Service vulnerability
        Number:     20020408-01-I
        Date:       April 30, 2002
        Reference:  CAN-2002-0172
______________________________________________________________________________

- -----------------------
- --- Issue Specifics ---
- -----------------------

SGI has determined that the default permissions on /dev/ipfilter as created
by /dev/MAKEDEV could lead to a Denial of Service attack.  The default
permissions were 644, and while the permissions are set to that value it is
possible for a non-root user to disrupt network traffic.

SGI has investigated the issue and recommends the following steps for
neutralizing the exposure.  It is HIGHLY RECOMMENDED that these measures be
implemented on ALL vulnerable SGI systems.


- --------------
- --- Impact ---
- --------------

The /dev/ipfilter device is created by default on IRIX 6.5 systems during
installation.  The ipfilterd software that is intended to use this device is
not installed by default, it is part of the eoe.sw.ipgate package.

To determine if you are vulnerable, execute the following command:

   $ ls -l /dev/ipfilter
   crw-r--r--    1 root     sys        59,  0 Apr 12 08:33 /dev/ipfilter

If your /dev/ipfilter shows the permissions and ownership of 644 as in the
example above, then you are vulnerable.

These vulnerabilities may not be exploited by a remote user, a local account
is required.

This issue has been corrected in IRIX 6.5.11 and later versions.

This vulnerability was assigned the following CVE:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2002-0172


- ----------------------------
- --- Temporary Workaround ---
- ----------------------------

You can fix the permissions of /dev/ipfilter with the following command:

   # chmod 600 /dev/ipfilter

After running that command, it should look like this:

   # ls -l /dev/ipfilter
   crw-------    1 root     sys        59,  0 Apr 12 08:33 /dev/ipfilter

However, SGI recommends upgrading to IRIX 6.5.11 or later because if the
/dev/MAKEDEV script is run it will reset the permissions to 644.  The
/dev/MAKEDEV script has been changed in IRIX 6.5.11 to create the device
with 600 permissions.


- ----------------
- --- Solution ---
- ----------------

SGI has not provided patches for this vulnerability. Our recommendation is
to upgrade to IRIX 6.5.11 or later.


   OS Version     Vulnerable?     Patch #      Other Actions
   ----------     -----------     -------      -------------
   IRIX 3.x        unknown                     Note 1
   IRIX 4.x        unknown                     Note 1
   IRIX 5.x        unknown                     Note 1
   IRIX 6.0.x      unknown                     Note 1
   IRIX 6.1        unknown                     Note 1
   IRIX 6.2        unknown                     Note 1
   IRIX 6.3        unknown                     Note 1
   IRIX 6.4        unknown                     Note 1
   IRIX 6.5          yes                       Notes 2 & 3
   IRIX 6.5.1        yes                       Notes 2 & 3
   IRIX 6.5.2        yes                       Notes 2 & 3
   IRIX 6.5.3        yes                       Notes 2 & 3
   IRIX 6.5.4        yes                       Notes 2 & 3
   IRIX 6.5.5        yes                       Notes 2 & 3
   IRIX 6.5.6        yes                       Notes 2 & 3
   IRIX 6.5.7        yes                       Notes 2 & 3
   IRIX 6.5.8        yes                       Notes 2 & 3
   IRIX 6.5.9        yes                       Notes 2 & 3
   IRIX 6.5.10       yes                       Notes 2 & 3
   IRIX 6.5.11       no
   IRIX 6.5.12       no
   IRIX 6.5.13       no
   IRIX 6.5.14       no
   IRIX 6.5.15       no
   IRIX 6.5.16       no


   NOTES

     1) This version of the IRIX operating has been retired. Upgrade to an
        actively supported IRIX operating system.  See
        http://support.sgi.com/irix/news/index.html#policy for more
        information.

     2) If you have not received an IRIX 6.5.X CD for IRIX 6.5, contact your
        SGI Support Provider or URL: http://support.sgi.com/irix/swupdates/

     3) Upgrade to IRIX 6.5.11 or later.


- -------------
- --- Links ---
- -------------

SGI Security Advisories can be found at:
http://www.sgi.com/support/security/ and
ftp://patches.sgi.com/support/free/security/advisories/

SGI Security Patches can be found at:
http://www.sgi.com/support/security/ and
ftp://patches.sgi.com/support/free/security/patches/

SGI patches for IRIX can be found at the following patch servers:
http://support.sgi.com/irix/ and ftp://patches.sgi.com/

SGI freeware updates for IRIX can be found at:
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SGI fixes for SGI open sourced code can be found on:
http://oss.sgi.com/projects/

SGI patches and RPMs for Linux can be found at:
http://support.sgi.com/linux/ or
http://oss.sgi.com/projects/sgilinux-combined/download/security-fixes/

SGI patches for Windows NT or 2000 can be found at:
http://support.sgi.com/nt/

IRIX 5.2-6.4 Recommended/Required Patch Sets can be found at:
http://support.sgi.com/irix/ and ftp://patches.sgi.com/support/patchset/

IRIX 6.5 Maintenance Release Streams can be found at:
http://support.sgi.com/colls/patches/tools/relstream/index.html

IRIX 6.5 Software Update CDs can be obtained from:
http://support.sgi.com/irix/swupdates/

The primary SGI anonymous FTP site for security advisories and patches is
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For security and patch management reasons, ftp.sgi.com (mirrors
patches.sgi.com security FTP repository) lags behind and does not do a
real-time update.


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______________________________________________________________________________
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