Re: Local FreeBSD, Openbsd, NetBSD, DoS Vulnerability

[bright () WINTELCOM NET (Alfred Perlstein)]

* Ussr Labs <labs () USSRBACK COM> [000602 13:08] wrote:
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> Local FreeBSD, Openbsd, NetBSD, DoS Vulnerability

[snip same old story about exhausting mbufs]

FreeBSD 4 and above are not vulnerable if proper limits are put
into place.  These limits should be setup at the same time other
limits (such as 'maxproc' to disallow forkbombing) are set up.

Please see the the RLIMIT_SBSIZE option for setrlimit(2), it allows
a reasonable limit to be set for users socket buffers.

An undocumeted (which I just fixed) option for login.conf(5) 'sbsize'
allows this restriction to be put into place for users:

        :sbsize=1048576:\

Of course the real solution is rmuser(8), but that's a matter of
policy.

hope this helps,

--
-Alfred Perlstein - [bright () wintelcom net|alfred () freebsd org]
"I have the heart of a child; I keep it in a jar on my desk."