On 14 Jun 2005 08:12:17 -0400, rumours say that Dan Sommers
<me@privacy.net > might have written:
On Tue, 14 Jun 2005 11:52:13 +0200,
Denis WERNERT <pe************ @yahoo.com> wrote:
The script could be SUID Root, and you could use os.setuid immediately
after having performed the task to switch to a non-priviledged
user. May be a big security risk, if someone can alter the script, he
gains root access to the system...
I am *not* advocating suid scripts, and *ESPECIALLY NOT* suid Python
programs, but if a user can modify an unwriteable suid script owned by
root in a an unwriteable directory, then they already have root access
to the system (unless there's' a kernel or filesystem bug, in which case
all bets are off anyway).
I believe that the suid bit on scripts (either *sh or python) is
completely ignored on most *nix systems.
Try this in a shell (bash or ksh) as a sudo-capable user:
echo hello >/tmp/tmp
sudo chown root /tmp/tmp
sudo chmod 600 /tmp/tmp
cat >/tmp/ax.py <<@
#!/usr/bin/env python
x = open("/tmp/tmp", "w")
x.write("there" )
x.close()
@
sudo chown root /tmp/ax.py
sudo chmod a=rx,u+s /tmp/ax.py
ls -l /tmp/ax.py /tmp/tmp
/tmp/ax.py
I get:
-r-sr-xr-x 1 root users 75 2005-06-14 16:15 /tmp/ax.py
-rw------- 1 root users 6 2005-06-14 16:15 /tmp/tmp
Traceback (most recent call last):
File "/tmp/ax.py", line 2, in ?
x = open("/tmp/tmp", "w")
IOError: [Errno 13] Permission denied: '/tmp/tmp'
--
TZOTZIOY, I speak England very best.
"Be strict when sending and tolerant when receiving." (from RFC1958)
I really should keep that in mind when talking with people, actually...
