[Debian 2.0] /usr/bin/suidexec gives root access

[roessler () GUUG DE (Thomas Roessler)]

Executive summary: /usr/bin/suidexec gives every user a
root shell.  Remove it.

tlr

----- Forwarded message from Thomas Roessler <roessler () guug de> -----

Date: Tue, 28 Apr 1998 15:21:17 +0200
From: Thomas Roessler <roessler () guug de>
Subject: suidmanager: SECURITY BREACH: /usr/bin/suidexec gives root access to every user on the system
To: submit () bugs debian org

Package: suidmanager
Version: 0.18

[This report also goes to the bugtraq mailing list.]

/usr/bin/suidexec will execute arbitrary commands as root,
as soon as just _one_ suid root shell script can be found
on the system: Just invoke

         /usr/bin/suidexec <your program> /path/to/script

- it will happily execute your program with euid = 0. This
is completely sufficient for doing arbitrary damage on the
system.

Additionally, suidexec will fail with shells which close
all but the "standard" file descriptorson startup:
/proc/self/fd/<N> (which is the file descriptor suidexec
has opened for the shell script in question) will have
vanished after this.  I am actually considering this a
feature, as it avoids some of the $HOME/.cshrc related
standard exploits.

SOLUTION: Just drop suidexec from the distribution. Trying
to do setuid shell scripts is almost always a bad idea. If
you absolutely need such things, use sudo.

-- System Information
Debian Release: 2.0 (frozen)
Kernel Version: Linux sobolev 2.0.33 #16 Sun Apr 19 23:48:02 MEST 1998 i586 unknown

Versions of the packages suidmanager depends on:
libc6   Version: 2.0.7pre1-4


----- End forwarded message -----

--
Thomas Roessler · 74a353cc0b19 · dg1ktr · http://home.pages.de/~roessler/
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