AUSCERT External Security Bulletin Redistribution

                     ESB-97.107 -- SGI Security Advisory
		   IRIX ftpd Signal Handling Vulnerability
                              19 August 1997


Silicon Graphics Inc. has released the following advisory concerning a
vulnerability in signal handling in the ftpd program.  This vulnerability
may allow local and remote users to read and write arbitary files.

The following security bulletin is provided as a service to AUSCERT's
members.  As AUSCERT did not write this document, AUSCERT has had no
control over its content.  As such, the decision to use any or all of this
information is the responsibility of each user or organisation, and should
be done so in accordance with site policies and procedures.

Contact information for SGI is included in the Security Bulletin below.
If you have any questions or need further information, please contact them

Previous advisories and external security bulletins can be retrieved from:


If you believe that your system has been compromised, contact AUSCERT or your
representative in FIRST (Forum of Incident Response and Security Teams).

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 4477
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
	AUSCERT personnel answer during Queensland business hours
	which are GMT+10:00 (AEST).
	On call after hours for emergencies.

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                Silicon Graphics Inc. Security Advisory

        Title:   IRIX ftpd Signal Handling Vulnerability
        Number:  19970801-01-PX
        Date:    August 15, 1997

Silicon Graphics provides this information freely to the SGI user community
for its consideration, interpretation, implementation and use.   Silicon
Graphics recommends that this information be acted upon as soon as possible.

Silicon Graphics provides the information in this Security Advisory on
an "AS-IS" basis only, and disclaims all warranties with respect thereto,
express, implied or otherwise, including, without limitation, any warranty
of merchantability or fitness for a particular purpose.  In no event shall
Silicon Graphics be liable for any loss of profits, loss of business, loss
of data or for any indirect, special, exemplary, incidental or consequential
damages of any kind arising from your use of, failure to use or improper
use of any of the instructions or information in this Security Advisory.

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

The ftpd(1M) program is the Internet File Transfer Protocol server process
that listens for incoming service requests.

As part of normal operation of the ftpd program, various service signals
are received and handled.  Due to a race condition with this signal
handling, a vulnerability can result that allows the manipulation of
files with root privileges.

Silicon Graphics Inc. has investigated the issue and recommends the
following steps for neutralizing the exposure.  It is HIGHLY RECOMMENDED
that these measures be implemented on ALL SGI systems.  This issue will
be corrected in future releases of IRIX.

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

The ftpd program (/usr/etc/ftpd) is installed on all IRIX systems by

For this particular vulnerability, a local account is not required.
Furthermore, the vulnerability can be exploited remotely.

Utilizing this vulnerability, files may be arbitrarily read and written
with root privileges.

This vulnerability has been reported in AUSCERT Advisory AA-97.03 and
CERT Advisory CA-97.16.

- - --------------------------
- - --- Temporary Solution ---
- - --------------------------

Although patches are available for this issue, it is realized that
there may be situations where installing the patches immediately may
not be possible.

The steps below can be used to remove the vulnerability by disabling
the ftpd program.  NOTE:  When disabled, ftp oriented connections will
not be possible in or out of the system.

     1) Become the root user on the system.

                % /bin/su -

     2) Edit the file /etc/inetd.conf (for IRIX 5.3 and lower,
      edit /usr/etc/inetd.conf).  Place a "#" as the first
      character of the ftp line to comment out and
      deactivate the service.

                # vi  /etc/inetd.conf

        {Find the following line}

             ftp   stream  tcp   nowait  root   /usr/etc/ftpd   ftpd -l

        {Place a "#" as the first character of the ntalk line}

             #ftp   stream  tcp   nowait  root   /usr/etc/ftpd   ftpd -l

        {Save the file and exit}

     3) Force inetd to re-read the configuration file.

                # /etc/killall -HUP inetd

     4) Return to previous level.

                # exit

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

   OS Version     Vulnerable?     Patch #      Other Actions
   ----------     -----------     -------      -------------

   IRIX 3.x          yes          not avail    Note 1
   IRIX 4.x          yes          not avail    Note 1
   IRIX 5.0.x        yes          not avail    Note 1
   IRIX 5.1.x        yes          not avail    Note 1
   IRIX 5.2          yes          not avail    Note 1
   IRIX 5.3          yes          2292
   IRIX 6.0.x        yes          not avail    Note 1
   IRIX 6.1          yes          not avail    Note 1
   IRIX 6.2          yes          1485
   IRIX 6.3          no
   IRIX 6.4          no


     1) upgrade operating system or see "Temporary Solution" section.

Patches are available via anonymous FTP and your service/support provider.

The SGI anonymous FTP site is sgigate.sgi.com ( or its
mirror, ftp.sgi.com.   Security information and patches can be found
in the ~ftp/security and ~ftp/patches directories, respectfully.

                 ##### Patch File Checksums ####

The actual patch will be a tar file containing the following files:

Filename:                 README.patch.1485
Algorithm #1 (sum -r):    14910 14 README.patch.1485
Algorithm #2 (sum):       18189 14 README.patch.1485
MD5 checksum:             ADB6A0762E278A45998D98CEF500F084

Filename:                 patchSG0001485
Algorithm #1 (sum -r):    12066 5 patchSG0001485
Algorithm #2 (sum):       43246 5 patchSG0001485
MD5 checksum:             F9412E4C328CDCAD6DD58FFCDAA95FC5

Filename:                 patchSG0001485.eoe_man
Algorithm #1 (sum -r):    36966 23 patchSG0001485.eoe_man
Algorithm #2 (sum):       48592 23 patchSG0001485.eoe_man
MD5 checksum:             79F0F83A0C96F20CB18D56E04548456B

Filename:                 patchSG0001485.eoe_sw
Algorithm #1 (sum -r):    28352 1073 patchSG0001485.eoe_sw
Algorithm #2 (sum):       49664 1073 patchSG0001485.eoe_sw
MD5 checksum:             AB8A52D58219A05A5D4BC9B0775A1218

Filename:                 patchSG0001485.idb
Algorithm #1 (sum -r):    35926 8 patchSG0001485.idb
Algorithm #2 (sum):       45831 8 patchSG0001485.idb
MD5 checksum:             60AF5CE37333674ED5806A4108E9E682

Filename:                 patchSG0001485.netman_data_man
Algorithm #1 (sum -r):    56900 15 patchSG0001485.netman_data_man
Algorithm #2 (sum):       58999 15 patchSG0001485.netman_data_man
MD5 checksum:             42BEB35E700813967F637E9BB0640385

Filename:                 patchSG0001485.nfs_man
Algorithm #1 (sum -r):    05186 17 patchSG0001485.nfs_man
Algorithm #2 (sum):       21113 17 patchSG0001485.nfs_man
MD5 checksum:             F090E7476C01DC64F12F3A094EFAD64B

Filename:                 patchSG0001485.nfs_sw
Algorithm #1 (sum -r):    20081 73 patchSG0001485.nfs_sw
Algorithm #2 (sum):       625 73 patchSG0001485.nfs_sw
MD5 checksum:             A770134D811CD1F9BEE62E86E9E7A121

Filename:                 README.patch.2292
Algorithm #1 (sum -r):    42992 50 README.patch.2292
Algorithm #2 (sum):       19871 50 README.patch.2292
MD5 checksum:             45C02D1F732F1306A8E01C9B41632081

Filename:                 patchSG0002292
Algorithm #1 (sum -r):    21569 28 patchSG0002292
Algorithm #2 (sum):       48653 28 patchSG0002292
MD5 checksum:             1118D1F3E3DE2F7BA6720E21F8E79288

Filename:                 patchSG0002292.dev_hdr
Algorithm #1 (sum -r):    55046 18 patchSG0002292.dev_hdr
Algorithm #2 (sum):       21666 18 patchSG0002292.dev_hdr
MD5 checksum:             12D756C9AAADDA464F628FB08B8012C2

Filename:                 patchSG0002292.eoe1_man
Algorithm #1 (sum -r):    58486 19 patchSG0002292.eoe1_man
Algorithm #2 (sum):       19828 19 patchSG0002292.eoe1_man
MD5 checksum:             971A700918352743FDFAD9DC7AAC7F08

Filename:                 patchSG0002292.eoe1_sw
Algorithm #1 (sum -r):    44489 3870 patchSG0002292.eoe1_sw
Algorithm #2 (sum):       46581 3870 patchSG0002292.eoe1_sw
MD5 checksum:             3A1228F719826BE5FAC06BC2610D9FE0

Filename:                 patchSG0002292.eoe2_man
Algorithm #1 (sum -r):    20509 16 patchSG0002292.eoe2_man
Algorithm #2 (sum):       64242 16 patchSG0002292.eoe2_man
MD5 checksum:             B0491FEFB0CE1C0BC03F7A1345BDE250

Filename:                 patchSG0002292.eoe2_sw
Algorithm #1 (sum -r):    04632 1401 patchSG0002292.eoe2_sw
Algorithm #2 (sum):       22409 1401 patchSG0002292.eoe2_sw
MD5 checksum:             668865304DC6C3669B6D3E84AF43821A

Filename:                 patchSG0002292.idb
Algorithm #1 (sum -r):    56516 52 patchSG0002292.idb
Algorithm #2 (sum):       26358 52 patchSG0002292.idb
MD5 checksum:             EC5A3C0A1CE3953F71354CDFA1A6052A

Filename:                 patchSG0002292.nfs_man
Algorithm #1 (sum -r):    22345 17 patchSG0002292.nfs_man
Algorithm #2 (sum):       21111 17 patchSG0002292.nfs_man
MD5 checksum:             8782FA52CAB650472352DABC1C38B823

Filename:                 patchSG0002292.nfs_sw
Algorithm #1 (sum -r):    19426 162 patchSG0002292.nfs_sw
Algorithm #2 (sum):       7929 162 patchSG0002292.nfs_sw
MD5 checksum:             E298C481D601E57F24BCAF30173BB304

- - ------------------------
- - --- Acknowledgments ---
- - ------------------------

Silicon Graphics Inc. wishes to thank the CERT Coordination Center
and AUSCERT for their assistance in this issue.

- - -----------------------------------------------------------
- - --- Silicon Graphics Inc. Security Information/Contacts ---
- - -----------------------------------------------------------

If there are questions about this document, email can be sent to


Silicon Graphics provides security information and patches for
use by the entire SGI community.  This information is freely
available to any person needing the information and is available
via anonymous FTP and the Web.

The primary SGI anonymous FTP site for security information and patches
is sgigate.sgi.com (  Security information and patches
are located under the directories ~ftp/security and ~ftp/patches,
respectively. The Silicon Graphics Security Headquarters Web page is
accessible at the URL http://www.sgi.com/Support/security/security.html.

For issues with the patches on the FTP sites, email can be sent to

For assistance obtaining or working with security patches, please
contact your SGI support provider.


Silicon Graphics provides a free security mailing list service
called wiretap and encourages interested parties to self-subscribe
to receive (via email) all SGI Security Advisories when they are
released. Subscribing to the mailing list can be done via the Web
(http://www.sgi.com/Support/security/wiretap.html) or by sending email
to SGI as outlined below.

% mail wiretap-request@sgi.com
subscribe wiretap <YourEmailAddress>

In the example above, <YourEmailAddress> is the email address that you
wish the mailing list information sent to.  The word end must be on a
separate line to indicate the end of the body of the message. The
control-d (^d) is used to indicate to the mail program that you are
finished composing the mail message.


Silicon Graphics provides a comprehensive customer World Wide Web site.
This site is located at http://www.sgi.com/Support/security/security.html.


For reporting *NEW* SGI security issues, email can be sent to
security-alert@sgi.com or contact your SGI support provider.  A
support contract is not required for submitting a security report.

  This information is provided freely to all interested parties and may
  be redistributed provided that it is not altered in any way, Silicon
  Graphics is appropriately credited and the document retains and
  includes its valid PGP signature.

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