Transparent hijacking of SMTP submission...

Randy Bush randy at psg.com
Sat Nov 29 15:37:56 UTC 2014


> I don't see this in my home market, but I do see it in someone else's...
> I kind of expect this for port 25 but...
> 
> J at mb-aye:~$telnet 147.28.0.81 587
> Trying 147.28.0.81...
> Connected to nagasaki.bogus.com.
> Escape character is '^]'.
> 220 nagasaki.bogus.com ESMTP Sendmail 8.14.9/8.14.9; Thu, 27 Nov 2014
> 19:17:44 GMT
> ehlo bogus.com
> 250-nagasaki.bogus.com Hello XXXXXXXXXXXXXXX.wa.comcast.net
> [XXX.XXX.XXX.XXX], pleased to meet you
> 250 ENHANCEDSTATUSCODES
> 
> J at mb-aye:~$telnet 2001:418:1::81 587
> Trying 2001:418:1::81...
> Connected to nagasaki.bogus.com.
> Escape character is '^]'.
> 220 nagasaki.bogus.com ESMTP Sendmail 8.14.9/8.14.9; Thu, 27 Nov 2014
> 19:18:33 GMT
> ehlo bogus.com
> 250-nagasaki.bogus.com Hello
> [IPv6:2601:7:2380:XXXX:XXXX:XXXX:c1ae:7d73], pleased to meet you
> 250-ENHANCEDSTATUSCODES
> 250-PIPELINING
> 250-8BITMIME
> 250-SIZE
> 250-DSN
> 250-AUTH DIGEST-MD5 CRAM-MD5 LOGIN
> 250-STARTTLS
> 250-DELIVERBY
> 250 HELP
> 
> that's essentially a downgrade attack on my ability to use encryption
> which seems to be in pretty poor taste frankly.

i think of it as an intentional traffic hijack.  i would be talking to a
lawyer.

randy, who plans to test next time he is behind comcast


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