Re: Strange SMTP Garbage Flood

From: Duncan Simpson (dpsat_private)
Date: Wed Nov 14 2001 - 08:49:35 PST

  • Next message: Johannes Verelst: "Re: Strange SMTP Garbage Flood"

    Incomplete mail sessions, i.e. HELO, MAIL FROM:, RCPT TO: followed by either
    cutting the connection or QUIT or RSET is also a known method of probing for
    valid aliases or user names. It almost always works even if the VRFY, EXPN and
    other more obvious methods have been disabled. It also tends to avoid null 
    mail session detectora.
    
    I have used this method more than once to find out if abuse@<domain> exists or
    not (and almost always throw in a known invalid name to see if the method
    works). The same method could be abused to probe for valid user names and that
    sort of thing.
    
    -- 
    Duncan (-:
    "software industry, the: unique industry where selling substandard goods is
    legal and you can charge extra for fixing the problems."
    
    
    
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