Hello, > Everybody knows that files with a suid bit set can be dangerous.
yes :) sgids too :) > Well, i was asking myself today why exactly linux uses the suid bit files?! because binaries are executed with almost the same rights as the user-owner-of-file [effective UID] > Could someone please explain that to me? > Example: > ~$ ls -lah /var/spool/cron/crontabs/user > -rw------- 1 root user 408 Apr 16 where are you have any suid ? I dont see any. > Ok, the suid is set for the crontab binary because you have to edit the root > owned file. # ls -l `which crontab ` -rwsr-xr-x 1 root root 22460 Oct 1 2001 /usr/bin/crontab yes, because only in this condition normal user can set crontab rules. man: /usr/bin/crontab crontab needs to be suid root to edit crontab files in /usr/spool/cron/crontabs and to signal() cron. If you disable suid for crontab binary this will be like that: $ crontab -l seteuid: Operation not permitted I am thinking about changing directory from /var/spool.... to another but ... signals..... I don't know. Maybe sombody know ? Everybody are agree with me ? > But why is it owned by root in the first place? I dont know, maybe root-owned [setuided] binary crontab set it ? And why ? because - when - user will be able to write to this file - he will be able to write to partition where /var/spool/cron/crontabs/ is mounted. -- Pozdrawiam, Marcin. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
