Skip site navigation (1)Skip section navigation (2)
Date:      22 Nov 2005 14:48:46 -0500
From:      Lowell Gilbert <freebsd-security-local@be-well.ilk.org>
To:        freebsd-security@freebsd.org
Subject:   Re: Need urgent help regarding security
Message-ID:  <44br0cqx9d.fsf@be-well.ilk.org>
In-Reply-To: <20051122112344.U18517@roble.com>
References:  <20051122120112.9D83516A423@hub.freebsd.org> <20051122075050.I81101@roble.com> <43836D25.5000101@kernel32.de> <20051122112344.U18517@roble.com>

next in thread | previous in thread | raw e-mail | index | archive | help

> >Be careful with adding ip addresses to deny via a packet filter.
> >If an attacker uses spoofed IP adresses, you may produce yourself
> >easily a denial of service attack.
> 
> Not sure I agree with the easily part.  TCP transport plus SSH
> protocol spoofing is not a vector that normally needs to be secured
> beyond what is already done in the kernel and router.  That's not to
> say such spoofing cannot be done, just that it is rare and would
> require a compromised router or localnet host at a minimum.

Except that it doesn't require spoofed addresses.  One attacker from the
local university's computer center (or from a large shell service ISP)
could lock out all of the other users on that machine.  Trivially.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?44br0cqx9d.fsf>