solaris root-setuid script to gain root?

From: Vitalik N. (robert.morris.jr@gmail.com)
Date: Sat Jun 30 2007 - 07:23:59 EDT


Hi

I was doing pen testing the other day and I found one root suid script
left by some of the web developers:

-rwsr-x--x 1 root users /home/web/c.cgi

which is basically a bash script:

------ cut ------------
#!/bin/sh

uname
------ cut ------------

And our system was recently compromised. Some local user was able to
gain root access. Could this script be the way of gaining root access?

According to http://www.unix.com/tips-and-tutorials/36711-the-whole-story-on-usr-bin-ksh.html
"Because it was not possible to write a secure suid shell script, the concept
of suid shell scripts was removed from Unix." But then it says "Solaris now
supports suid shell" !
I tried modifying the PATH variable and creating my own "uname" program.
But my uname program runs with local user privs instead of root. I
also tried the
other attack described in the link above: "link to -i" but this didn't
work as well.
So could this script be the problem?

P.S: The machine runs SunOS 5.6 with all updates

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