Re: hard links create local DoS vulnerability and security problems

Valdis.Kletnieks
2003-11-24T18:23:03Z

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On Mon, 24 Nov 2003 13:10:46 EST, "Richard B. Johnson" said:

> # chmod 4755 xxx
> # su johnson
> $ cp /tmp/xxx .
> $ ls -la xxx
> -rwxr-xr-x 1 rjohnson guru 4887 Nov 24 12:57 xxx
^ Hmm.. this sucker is mode 755, not 4755...

> This clearly shows that once the file exists in a non-root
> directory, it will not function as setuid root.

No, what it shows is that once you *copy* the file to another file,
and the second file isn't set-UID, it won't run as set-UID anymore.

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