Re: Mozilla Thunderbird SMTP down-negotiation weakness

> The "TLS, if available" option is common to most MUAs and is a serious
> security problem.

        As is every other mainstream application of TLS/SSL I've ever seen
coded into a mainstream application. Don't just pick on Thunderbird
for it - applications using TLS/SSL typically make MITM easy by design,
rather than difficult.

        Sit you your faviorite wireless network and MITM your faviorite ssl
web sites off it. If your user population is very intelligent, maybe
only 9 out of 10 will click the "Windows is annoying me with a box and
an OK button - I will click OK to keep going" popup and ignore the
certificate mismatch utterly. Otherwise the only hard part will be
finding a user that doesn't ignore the mismatch - it's so easy to
get passwords this way it isn't even sporting. It's like whacking baby
seals with a stick.

        SSL/TLS applications are just the latest most fertile ground where
software designers have put in a crutches for lazy stupid people thereby
rendering something kinda ok into something mostly useless. 

        -Bob
--
Bob Beck                                                             AICT
beck@bofh.ucs.ualberta.ca                           University of Alberta
if ((not 0 && not 1)!=(!0 && !1)){print "I want what Larry and Tom smoke!\n";}