Controlling read access

John Almberg jalmberg at identry.com
Wed Aug 6 16:33:46 UTC 2008


> | Now I have just one major league problem: when I logged in as one  
> of the
> | users, to test the connections, I discovered that I had SUPER  
> POWERS. I
> | was able to delete any file that I could see, including ones that  
> were
> | owned by root. Digging uncovered the fact that pure-ftpd runs  
> with root
> | privileges... not so good for my situation.
> |
> | My guess is I need to compile with the --with-privsep switch  
> turned on...
> |
> | So, finally I have a real FreeBSD question!
> |
> | What is the proper way, in ports, to set a configuration flag?  
> The only
> | way I could figure out was to add it to the Makefile.
> |     PRIVSEP "Enable privilege separation" on \
> |
> | If this is the correct way to turn this compile switch on, it  
> doesn't
> | seem to work. After running:
> |
> | make deinstall
> | make config         # checking the privilage separation box
> | make reinstall
> |
> | The logged in user can still delete any file, regardless of  
> permissions
> | or ownership. This is clearly a problem... I don't want my users  
> to be
> | able to blow away their own websites while they are uploading some
> | images. I am still digging for info on this problem. Any  
> thoughts, much
> | appreciated!
> |
> | -- John
> |
>
> Hi John,
>
> Try this sequence instead, and you should be all set:
>
>
> make deinstall
> make clean
> make config (skip this if you've already chosen the options you want)
> make install
>
> The clean target will make sure that your environment is reset back  
> to a
> known state.  The install target will then perform a fresh build and
> install with the privsep option enabled.  If you already had  
> binaries in
> your port directory, then the reinstall target installs them without
> rebuilding, as far as I can tell from reading /usr/ports/Mk/ 
> bsd.port.mk.
>

Hi Greg,

I tried your sequence, but it didn't seem to work. Or, perhaps it  
worked and the PRIVSEP option doesn't do what I expect it to. Logging  
in as a normal user gives that user root privileges.

This seems pretty scary to me. Not so bad, since the user is locked  
into his own directory, but enough power to hurt themselves, which is  
too much power, IMHO. My users aren't experts. I can definitely see  
them clicking the delete key by accident.

Back to digging for info...

Thanks: John




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