IRIX 3.3 and 3.31 /usr/sbin/Mail

Original issue date: October 31, 1990
Last revised: September 17, 1997
Attached Copyright statement

A complete revision history is at the end of this file.

The CERT/CC has received the following report of a vulnerability in /usr/sbin/Mail, present only in IRIX 3.3 and 3.3.1.  This information was provided to the CERT/CC by Robert Stephens, of Silicon Graphics Inc.

I. Description

/usr/sbin/Mail can fail to reset its group id to the group id of the caller.

II. Impact

Can allow any user logged onto the system to read any other user's (including root's) mail.

III. Solution

A fixed /usr/sbin/Mail binary has been made available for anonymous ftp from SGI.COM ([]).  The correct binary can be found at:


under the ftp directory.

Note that this binary must be installed with the same group (mail) and permissions (2755) as your existing 3.3 or 3.3.1 /usr/sbin/Mail.

For further questions, please contact your Silicon Graphics support center (Geometry Partners HOTLINE number: (800) 345-0222)

This document is available from:

CERT/CC Contact Information

Phone: +1 412-268-7090 (24-hour hotline)
Fax: +1 412-268-6989
Postal address:
CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh PA 15213-3890

CERT/CC personnel answer the hotline 08:00-17:00 EST(GMT-5) / EDT(GMT-4) Monday through Friday; they are on call for emergencies during other hours, on U.S. holidays, and on weekends.

Using encryption

We strongly urge you to encrypt sensitive information sent by email.  Our public PGP key is available from

If you prefer to use DES, please call the CERT hotline for more information.

Getting security information

CERT publications and other security information are available from our web site

* "CERT" and "CERT Coordination Center" are registered in the U.S. Patent and Trademark Office.

Any material furnished by Carnegie Mellon University and the Software Engineering Institute is furnished on an "as is" basis. Carnegie Mellon University makes no warranties of any kind, either expressed or implied as to any matter including, but not limited to, warranty of fitness for a particular purpose or merchantability, exclusivity or results obtained from use of the material. Carnegie Mellon University does not make any warranty of any kind with respect to freedom from patent, trademark, or copyright infringement.

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Copyright 1990 Carnegie Mellon University.

Revision History
September 17,1997  Attached Copyright Statement