Messages in this thread | | | Date | Mon, 29 Dec 1997 19:19:06 +0000 (GMT) | From | Bryn Paul Arnold Jones <> | Subject | Re: hardlinks.... sucks... ;-( |
| |
-----BEGIN PGP SIGNED MESSAGE-----
On Mon, 29 Dec 1997, Yuri Kuzmenko wrote:
> No, you are not right ;-( There is old Unix hole and you know it. And it's > a kernel vfs issue. In general, this is *huge* hole. Novice in > sysadmin's world can done this "not kernel issue": > > user$ ln /etc/passwd ~/.some > user$ mail root -s "Please, help me" > change pls my uid (and mount with this uid some nfs export from other > machine) > . > > ... > > root# chown newuser /home/user -R > > ... > > user$ ls -l /etc/passwd > -rw-r--r-- 1 newuser root 1053 Dec 22 20:13 /etc/passwd > user$ he-he-he > > This is only common example. And this is a *serious* security bug. >
This is called social enginering, and really isn't a kernel issue. It is a case for having a small root partition with things like /etc, /lib, /sbin, /dev and the like in which joe average user is never going to be allowed to write in, and having /home and /tmp as mount points, so hardlinks just arn't posable.
It then becomes a non issue. If chown dereferances symlinks (by default) then chown needs to be fixed (mine dosn't), but it's still a user space or admin problem.
Bryn - -- PGP Pub key http://www.gytha.demon.co.uk/pubkey.asc ID: 1024/30AF2D69 On-line, adj.: FP: FC 4E 41 9E 64 C3 AB 28 A3 5A 57 F8 CC D9 A7 B8 The idea that a human being should always be accessible to a computer.
-----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv Comment: Probably (spelt 'Proberbly') requires PGP version 2.6 or later ;)
iQCVAwUBNKf3rusaGi8wry1pAQGZ5AQAoq+okEUH3Tuz/IQK+EqTih+1Xh53lqST 9SE66RtvsNUhvJ0AkPJ5YdJWYUqVaIPnp1pgg51ku/o11OF2fsZemLc5+U/u121X i+E35LcGJ9pxXqSY6vG6iweuSf9XoAeMwiybR2QNjwVDAIc+1h0u8CGJesaD7lI+ bGFG9kVagSw= =paBi -----END PGP SIGNATURE-----
| |