Subject: IRIX Mail(1)/mailx(1) Security Issues

From: SGI Security Coordinator <[email-masked]>
Date: Tue, 29 Sep 1998 23:17:59 GMT

-----BEGIN PGP SIGNED MESSAGE-----

______________________________________________________________________________
                Silicon Graphics Inc. Security Advisory

        Title:   IRIX Mail(1)/mailx(1) Security Issues
        Number:  19980605-01-PX
        Date:    September 29, 1998
______________________________________________________________________________

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 Mail(1), also know as mail_bsd, and mailx(1) programs are used to send and
receive mail.

A buffer overrun was discovered in mailx(1) program that will allow an intruder
to manipulate any file that is owned by the mail group.

A security vulnerability was discovered in the Mail(1) program which can lead
to a root compromise.

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 vulnerable SGI systems.  This
issue will be corrected in future releases of IRIX.

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

The Mail(1)/mailx(1) program are installed by default on IRIX.

A user account on the vulnerable system is required in order to exploit
Mail(1)/mailx(1) locally and remotely.

The mailx(1) exploit can lead to mail group privileges.

The Mail(1) exploit can lead to root compromise of the system.

These vulnerabilities have been publicly discussed in Usenet newsgroups
and mailing lists.

- ----------------------------
- ----- 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 removing
the permissions of the Mail(1)/mailx(1) program.

     1) Become the root user on the system.

                % /bin/su -
                Password:
                #

     2) Remove the permissions on the vulnerable programs.

                # /bin/chmod 555 /usr/sbin/mailx
                # /bin/chmod 500 /usr/sbin/Mail

                           ************
                           *** NOTE ***
                           ************

            Removing group and other permissions from /usr/sbin/Mail
            will prevent non-root users from accessing the Mail(1) program.

     4) Verify the new permissions on the program.
        Note that the program size may be different depending on release.

                # ls -al /usr/sbin/mailx /usr/sbin/Mail

                -r-xr-xr-x    1 root  mail  171204 May 22 16:29 /usr/sbin/mailx
                -r-x------    1 root  mail  165864 Feb 12  1996 /usr/sbin/Mail

     5) Return to previous user level.

                # exit
                %

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

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

   IRIX 3.x          yes          not avail        Note 1, 2 & 3
   IRIX 4.x          yes          not avail        Note 1, 2 & 3
   IRIX 5.0.x        yes          not avail        Note 1, 2 & 3
   IRIX 5.1.x        yes          not avail        Note 1, 2 & 3
   IRIX 5.2          yes          not avail        Note 1, 2 & 3
   IRIX 5.3          yes           3347
   IRIX 6.0.x        yes          not avail        Note 1, 2 & 3
   IRIX 6.1          yes          not avail        Note 1, 2 & 3
   IRIX 6.2          yes           3348
   IRIX 6.3          yes           3394
   IRIX 6.4          yes           3394
   IRIX 6.5          yes          not avail        Note 4
   IRIX 6.5.1m       yes           3393            Note 5

   NOTES

     1) Upgrade to currently supported IRIX operating system.
     2) See "Temporary Solution" section for a workaround.
     3) Unsupported by SGI, "freeware" sendmail distributions can be found at
        http://www.sendmail.org/
     4) For IRIX 6.5, you must first install IRIX 6.5.1 Maintenance Release
        and then install patch 3393. If you have not received an IRIX
        6.5.1m CD for IRIX 6.5, contact your SGI Support Provider
        or download the Maintenance Release from http://support.sgi.com/
     5) Patchsets have been replaced with quarterly Maintenance Releases
        Streams starting with IRIX 6.5. Information about Maintenance Release
        Streams can be found in the IRIX 6.5 Technical Brief at:
        http://www.sgi.com/software/irix6.5/

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

The SGI anonymous FTP site is sgigate.sgi.com (204.94.209.1) or its
mirror, ftp.sgi.com.  Security information and patches can be found
in the ~ftp/security and ~ftp/patches directories, respectively.

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

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

Filename:                 README.patch.3347
Algorithm #1 (sum -r):    61881 11 README.patch.3347
Algorithm #2 (sum):       20212 11 README.patch.3347
MD5 checksum:             EC4353F140F0926BA1EAC5E8F6A47827

Filename:                 patchSG0003347
Algorithm #1 (sum -r):    61339 4 patchSG0003347
Algorithm #2 (sum):       55594 4 patchSG0003347
MD5 checksum:             FD956A1D65BD01717D95AF59CFDE9F72

Filename:                 patchSG0003347.eoe1_man
Algorithm #1 (sum -r):    11384 69 patchSG0003347.eoe1_man
Algorithm #2 (sum):       23294 69 patchSG0003347.eoe1_man
MD5 checksum:             E3201B231A10E89FF1376D1BA9DFBB65

Filename:                 patchSG0003347.eoe1_sw
Algorithm #1 (sum -r):    27750 850 patchSG0003347.eoe1_sw
Algorithm #2 (sum):       3662 850 patchSG0003347.eoe1_sw
MD5 checksum:             DDE33397D29F3CC17593FB68C98093F0

Filename:                 patchSG0003347.idb
Algorithm #1 (sum -r):    54110 7 patchSG0003347.idb
Algorithm #2 (sum):       20457 7 patchSG0003347.idb
MD5 checksum:             7F63FB32C0D3392909556D833ACF00A2

Filename:                 README.patch.3348
Algorithm #1 (sum -r):    02655 10 README.patch.3348
Algorithm #2 (sum):       52305 10 README.patch.3348
MD5 checksum:             6579FF9DBF69D8449FA41E62FA002D14

Filename:                 patchSG0003348
Algorithm #1 (sum -r):    25807 4 patchSG0003348
Algorithm #2 (sum):       47261 4 patchSG0003348
MD5 checksum:             12EED5A4099C1E63AFBE1C439339C71F

Filename:                 patchSG0003348.eoe_man
Algorithm #1 (sum -r):    01364 69 patchSG0003348.eoe_man
Algorithm #2 (sum):       23234 69 patchSG0003348.eoe_man
MD5 checksum:             AA90D2858E7D2BBD02A2FDE25685B1A2

Filename:                 patchSG0003348.eoe_sw
Algorithm #1 (sum -r):    42080 910 patchSG0003348.eoe_sw
Algorithm #2 (sum):       36251 910 patchSG0003348.eoe_sw
MD5 checksum:             DA8B126611F0D4C0B28E676919BB3D66

Filename:                 patchSG0003348.idb
Algorithm #1 (sum -r):    43633 7 patchSG0003348.idb
Algorithm #2 (sum):       20449 7 patchSG0003348.idb
MD5 checksum:             8F447F20F2828C12EC6CBF7E53686EF7

Filename:                 README.patch.3393
Algorithm #1 (sum -r):    16419 8 README.patch.3393
Algorithm #2 (sum):       46041 8 README.patch.3393
MD5 checksum:             CF5A08C1EACC7B8242E7BC05C914C6EC

Filename:                 patchSG0003393
Algorithm #1 (sum -r):    29657 3 patchSG0003393
Algorithm #2 (sum):       15111 3 patchSG0003393
MD5 checksum:             4B3CAFD8ED102F154DECCCAADF4760E0

Filename:                 patchSG0003393.eoe_man
Algorithm #1 (sum -r):    26033 69 patchSG0003393.eoe_man
Algorithm #2 (sum):       23233 69 patchSG0003393.eoe_man
MD5 checksum:             F03552977EA408EACB85B0772F3D3EC2

Filename:                 patchSG0003393.eoe_sw
Algorithm #1 (sum -r):    11507 1160 patchSG0003393.eoe_sw
Algorithm #2 (sum):       54353 1160 patchSG0003393.eoe_sw
MD5 checksum:             523494C66C94EA50E6C3D60E56B04E75

Filename:                 patchSG0003393.idb
Algorithm #1 (sum -r):    01437 8 patchSG0003393.idb
Algorithm #2 (sum):       38192 8 patchSG0003393.idb
MD5 checksum:             2EA142047CCD22B7E536A6720B9136A2

Filename:                 README.patch.3394
Algorithm #1 (sum -r):    22031 10 README.patch.3394
Algorithm #2 (sum):       40712 10 README.patch.3394
MD5 checksum:             89B34B7222723BFCA4220C18C2CA40E0

Filename:                 patchSG0003394
Algorithm #1 (sum -r):    61693 3 patchSG0003394
Algorithm #2 (sum):       32311 3 patchSG0003394
MD5 checksum:             23748EB8970E3CD8295C54E9AA8961BA

Filename:                 patchSG0003394.eoe_man
Algorithm #1 (sum -r):    26033 69 patchSG0003394.eoe_man
Algorithm #2 (sum):       23233 69 patchSG0003394.eoe_man
MD5 checksum:             F03552977EA408EACB85B0772F3D3EC2

Filename:                 patchSG0003394.eoe_sw
Algorithm #1 (sum -r):    55501 1153 patchSG0003394.eoe_sw
Algorithm #2 (sum):       4669 1153 patchSG0003394.eoe_sw
MD5 checksum:             5698C5642874FED5E95D9B5989BBF0D1

Filename:                 patchSG0003394.idb
Algorithm #1 (sum -r):    10153 8 patchSG0003394.idb
Algorithm #2 (sum):       36831 8 patchSG0003394.idb
MD5 checksum:             B85E01E783292D03AEF7778F14B61E18

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

Silicon Graphics wishes to thank the University of Alaska Fairbanks
Arctic Region Supercomputing Center and NASA Goddard Space Flight Center
for their assistance in this matter.

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

If there are questions about this document, email can be sent to
[email-masked].

                      ------oOo------

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 (204.94.209.1).  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
[email-masked].

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

                      ------oOo------

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^d

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                      ------oOo------

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                      ------oOo------

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______________________________________________________________________________
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