writing a program for root access?

[rocketpcguy]

i noticed this news item:
http://linuxtoday.com/news_story.php3?ltsn=2004-09-08-039-26-SC-SW

so star, a tape backup utility, can be used to get root access. so could not a local cracker write a program like the old un-updated star and run it to get root access?

[psi42]

AFAIK the program has to be suid root.

[X_console]

Any program that is SUID root has the potential of being exploited to give root priviledges if not properly coded. So technically you can write a program that will spawn a shell, but unless you can make it SUID root, it won't really be of much use.

[bwkaz]

And normal users cannot change the owner of any file. Only root can change the owner.

When a non-root user creates a file, they are (or rather their UID is) the owner of it. If they turn on the set-uid bit and make the file executable, this is allowed -- but it will not be suid root. It will be suid that-UID. They cannot make root own the file unless they are root (they also cannot make a suid-some-other-UID file unless they are root, because again, they can't change the owner of files).

[rocketpcguy]

thanks for the detailed explaination.