Focus on Linux
RE: spambots and dictionary attacks Nov 20 2006 11:17PM
Steven Jones (Steven Jones vuw ac nz) (2 replies)
Re: spambots and dictionary attacks Nov 22 2006 08:36AM
rowland onobrauche (rowland onobrauche legendplc com)
Re: spambots and dictionary attacks Nov 21 2006 11:04PM
Ansgar -59cobalt- Wiechers (bugtraq planetcobalt net) (1 replies)
Re: spambots and dictionary attacks Nov 22 2006 05:30PM
Kurt Seifried (bt seifried org) (2 replies)
Re: spambots and dictionary attacks Nov 23 2006 06:01PM
Ansgar -59cobalt- Wiechers (bugtraq planetcobalt net)
On 2006-11-22 Kurt Seifried wrote:
>> Greylisting is a two-edged sword, though, that may not only cause
>> noticable delays in mail delivery, but also legit mails to be
>> rejected.
>
> Only for the first email if the greylisting system has any sense (i.e.
> OpenBSD's spamd),

I'm not familiar with OpenBSD. How does its spamd work? Does it
whitelist hosts that have re-send a greylisted mail?

> plus most allow whitelisting.

You can only whitelist what you know about, so there's still the
possibility of legit mail being rejected.

>> Not to mention that it'll stop working as soon as it's being used
>> widely enough to make adjusting to it worthwhile to spammers.
>
> Sure and then the hosts are behaving like real email servers which is
> vastly more expensive (computationally/etc.) than just blasting stuff
> out.

True. But since botnets are cheap: why would a spammer care?

Don't get me wrong: I'm not advocating against greylisting here (though
personally I prefer to avoid it), I'm just pointing out that it's not a
silver bullet.

Regards
Ansgar
--
"All vulnerabilities deserve a public fear period prior to patches
becoming available."
--Jason Coombs on Bugtraq

[ reply ]
Re: spambots and dictionary attacks Nov 23 2006 05:40PM
Devdas Bhagat (devdas dvb homelinux org)


 

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