Re: Of mice and men

> So what does chmod do? Or do you somehow disable that from working?

Someone can only chmod or chown files that they have permission to do
so. So one can chmod _their_ files to give access to others, but they
cannot gain permission for themselves.

> Please check your system for programs set with the SUID bit
> enabled then tell me you cannot run something like root.

The suid bit on a program makes that program run as the owner of the
file. If I set my programs (ie ones that I own) to suid then they run
as my user and thus can access my files and directories. I could do
that so that others could run my program to access those files without
letting them access the files directly. ie it makes the files _more_
secure. As it is _my_ program then only I can set the suid and I can
control what the program does.

Sometimes the suid is set for root owned files. This can only be set by
root and cannot be set by, say, downloading a file and saving it to
disk. In fact downloading won't even set the executable bits.

The same argument applies. A suid root owned executable can, for
example, update a file that users only have read access to. Thus
ordinary users can only update via that program and they don't need
write access. It is _more_ secure.

.

Relevant Pages

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