It is possible for any host on the internet to send an SRS1 mail to an SRS
compliant host. That SRS compliant host will rewrite it unconditionally to
an SRS0 address and forward it to what is assumed to be another SRS
compliant host. I would argue the thesis that this is not a significant
vulnerability.
1) This does not create an "open relay".
An open relay is a host which will send mail on request to a specified
destination address. The SRS1 mechanism will only send mail to addresses
starting with "SRS0". These claims of "open channel into the mailer" are
amusing, but technically impossible and socially infeasible.
2) The generated SRS0 address will be invalid.
The final destination host is either SRS compliant, in which case the hash
will be invalid, or it is not, in which case it is highly unlikely that an
address 'srs0' will exist. If the final host has a catchall, then it is
expecting junkmail anyway.
3) This work is of no value to the spammer, and will therefore never be
done.
The spammer gains no information from performing this attack. It wastes
his bandwidth and resources, and there isn't even the slimmest chance of a
return.
4) This is of little use to DoS k1dd13s.
This is just like sending ping packets with a faked source address. These
cannot be detected either. There is no packet or mail multiplier here.
This takes as much of the k1dd13's bandwidth as of the victim's. And
anyway, the k1dd13s have bigger and better toys and easier ways to
"remove" hosts from the internet.
I feel like I'm playing a circular game of 20 questions.
"Is it square?"
"No, it isn't square."
"Then it must be round!"
"No, it isn't round."
"Then it's square."
"No, it still isn't square."
This mail is an attempt to explain that it isn't square or round. No doubt
I've missed triangular somewhere above, but I am doing my best. I will
include this explanation in my SRS paper when I get time to rewrite it.
I hereby leave certain parties to their shouting match. Again, I recommend
the publication of a web page containing a clear and concise explanation
of what is possible (a little), why it would be done (it wouldn't), and
who would do it (anyone who wins by doing it, i.e. no-one).
S.
--
Shevek http://www.anarres.org/
I am the Borg. http://www.gothnicity.org/
-------
To unsubscribe, change your address, or temporarily deactivate your subscription,
please go to http://v2.listbox.com/member/?listname=srs-discuss@v2.listbox.com
compliant host. That SRS compliant host will rewrite it unconditionally to
an SRS0 address and forward it to what is assumed to be another SRS
compliant host. I would argue the thesis that this is not a significant
vulnerability.
1) This does not create an "open relay".
An open relay is a host which will send mail on request to a specified
destination address. The SRS1 mechanism will only send mail to addresses
starting with "SRS0". These claims of "open channel into the mailer" are
amusing, but technically impossible and socially infeasible.
2) The generated SRS0 address will be invalid.
The final destination host is either SRS compliant, in which case the hash
will be invalid, or it is not, in which case it is highly unlikely that an
address 'srs0' will exist. If the final host has a catchall, then it is
expecting junkmail anyway.
3) This work is of no value to the spammer, and will therefore never be
done.
The spammer gains no information from performing this attack. It wastes
his bandwidth and resources, and there isn't even the slimmest chance of a
return.
4) This is of little use to DoS k1dd13s.
This is just like sending ping packets with a faked source address. These
cannot be detected either. There is no packet or mail multiplier here.
This takes as much of the k1dd13's bandwidth as of the victim's. And
anyway, the k1dd13s have bigger and better toys and easier ways to
"remove" hosts from the internet.
I feel like I'm playing a circular game of 20 questions.
"Is it square?"
"No, it isn't square."
"Then it must be round!"
"No, it isn't round."
"Then it's square."
"No, it still isn't square."
This mail is an attempt to explain that it isn't square or round. No doubt
I've missed triangular somewhere above, but I am doing my best. I will
include this explanation in my SRS paper when I get time to rewrite it.
I hereby leave certain parties to their shouting match. Again, I recommend
the publication of a web page containing a clear and concise explanation
of what is possible (a little), why it would be done (it wouldn't), and
who would do it (anyone who wins by doing it, i.e. no-one).
S.
--
Shevek http://www.anarres.org/
I am the Borg. http://www.gothnicity.org/
-------
To unsubscribe, change your address, or temporarily deactivate your subscription,
please go to http://v2.listbox.com/member/?listname=srs-discuss@v2.listbox.com
