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    SubjectRe: hardlinks.... sucks... ;-(

    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.

    - --
    PGP Pub key 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.

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