b-38.ciac.sgi-fmt-vulnerability Vulnerability in Silicon Graphics Inc. "IRIX" /usr/sbin/fmt
7fba0c152662263a8dcd148c33d4f7f430aff9c54cb34fbf082100e711000a78
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The Computer Incident Advisory Capability
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Information Bulletin
Vulnerability in Silicon Graphics Inc. "IRIX" /usr/sbin/fmt
August 29, 1991 08:15 PDT Number B-38
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PROBLEM: Misconfiguration of /usr/sbin/fmt on some SGI platforms
causes a breakdown of privacy for files in group MAIL.
PLATFORM: Silicon Graphics Inc. IRIX versions prior to 4.0 (including
all 3.2 and 3.3.X versions).
DAMAGE: A non-privileged user may read mail belonging to any user,
including root.
SOLUTIONS: Apply patch described below.
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Critical Facts about Vulnerability in /usr/sbin/fmt
CIAC has learned of a security problem with the text formatting
program /usr/sbin/fmt supplied by Silicon Graphics. The program will
allow any user to read mail messages or other files owned by group
"mail" on IRIX versions prior to 4.0 (including all 3.2 and 3.3.X
versions). This problem has been fixed in version 4.0. CIAC expects
this vulnerability to be widely exploited due to the recent release of
this information on various Internet information services. We highly
recommend that you apply this patch immediately.
Silicon Graphics has provided the enclosed patch instructions, and
they have been verified on our SGI IRIX System V Release 3.3.1
machine.
To correct this vulnerability, execute the following command as root:
chmod 755 /usr/sbin/fmt
Optionally, you could also change the owner and group of the file,
however, SGI has informed us that this change is not necessary:
chown root.sys /usr/sbin/fmt
If system software should ever be reloaded from a 3.2 or 3.3.*
installation tape or from a backup tape created before the patch was
applied, repeat the above procedure immediately after the software has
been reloaded (before enabling logins by normal users).
SGI customers can contact 1-800-800-4SGI for additional assistance.
For additional information or assistance, please contact CIAC:
David Brown
(415) 423-9878 or (FTS) 543-9878 before Sept 1, 1991
(510) 423-9878 or (FTS) 543-9878 after Sept 1, 1991
FAX: (415) 423-8002 or (FTS) 543-8002 before Sept 1, 1991
FAX: (510) 423-8002 or (FTS) 543-8002 after Sept 1, 1991
Note: On September 1, 1991, CIAC's area code will change
to 510.
or send e-mail to:
ciac@llnl.gov
The assistance of Silicon Graphics, CERT/CC, and Chuck Athey of
Lawrence Livermore National Laboratory is gratefully acknowledged.
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nor any of their employees, makes any warranty, expressed or implied,
or assumes any legal liability or responsibility for the accuracy,
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disclosed, or represents that its use would not infringe privately
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