Thread: dd+user=trouble
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Old 25th September 2008
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graudeejs graudeejs is offline
Real Name: Aldis Berjoza
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Join Date: Jul 2008
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Default dd+user=trouble

For some reason, i just realized something ODD.
As i see it's major security risk, unless you use disk encryption, or disable this little thing...

It occurred to me, that regular user can use dd. This can be done physically/remotely if user has accoun/or can log on with ssh

By default FreeBSD allows any user to use dd.
User can copy disk, and save it to custom medium/net or whatever....
Later he can go home, and using his own version of FreeBSD mount image.... and now as root.
He will have access to everything..... therefore if / is unencrypted, he can try to brute gess passwords.....

Solution is simple:
a) Only allow dd to root/wheel
b) encrypt everything
c) make sure user can't access /dev



OK, someone might know this, but for me [i use freebsd at home], this was shock....

Anyone got comments?


P.S. and i was fallowing
http://www.bsdguides.org/guides/free...ity/harden.php
to harden my system



EDIT: i didn't do much testing, it's late, i will do more tomorrow....
just realized, that i'm not sure if ordinary user can read /dev/....
worked for me, cause i'm wheel
And sorry if this is just false alarm



EDIT2: coundn't sleep.... it's all good, /dev/... can't be read by user....
Admin, plz delete this, i can't

Last edited by graudeejs; 25th September 2008 at 10:39 PM. Reason: My fault, /dev/ad, can't be read by user
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