Re: SECURITY.NNOV: The Bat! <cr> bug

From: Maxim Masiutin (maxat_private)
Date: Mon Apr 23 2001 - 03:40:38 PDT

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    Hello 3APA3A!
    
      The Bat! v1.42 Beta/10 released Sat, 21 Apr 2001 fixes CR handling
      that you've described. It is now strict to line endings. Only
      <CR><LF>.<CR><LF> is now treated as end of message.
    
    Mon, 23 Apr 2001 12:46:23 +0400, you wrote:
    
    mfb>>   This is not a bug of The Bat! but a bug of MTA (POP3/SMTP servers)
    mfb>>   that allow such odd messages. The proposed "bad-message"
    mfb>>   (http://www.security.nnov.ru/files/badmess.zip) is not
    mfb>>   RFC-compliant. Any RFC-compliant POP3/SMTP server must either bounce
    mfb>>   or cure it. I've used a proposed example to send the message to
    mfb>>   myself, on a FreeBSD server with Sendmail 8.11.1 I've typed
    mfb>>   cat badmess | sendmail -U maxat_private
    
    3> You're  wrong.  This  message  _is_ RFC 822 and RFC 1251 compliant. In
    3> fact,  RFC  822  absolutely  clear  allows  <CR> and <LF> even in some
    3> message headers:
    
    3>  text        =  <any CHAR, including bare    ; => atoms, specials,
    3>                      CR & bare LF, but NOT       ;  comments and
    3>                      including CRLF>             ;  quoted-strings are
    3>                                                  ;  NOT recognized.
    
    
    3> _any_  pop3  server  shouldn't  change  this message, because RFC 1939
    3> follows RFC 822 for message standard.
    
    
    3> RFC  821  (SMTP) simply says "The mail data may contain any of the 128
    3> ASCII character codes".
    
    
    3> RFC  1251 allow message to contains any binary data and strings of any
    3> length. In fact, sendmail allows any characters (including NULL) to be
    3> in message body. "badmess" was tested with sendmail 8.9.3 + mail.local
    3> + UW-pop3d 7.59.
    
    3> P.S.  I didn't tested The Bat! with NULL characters in message body...
    3> If something like
    
    3> <CR><LF>NULL.<CR><LF>-ERR
    
    3> in message body hurts The Bat! badly RitLabs better patch it right now
    3> :)
    
    
    
    
    
    
    --
    Maxim Masiutin
    Vice President, Ritlabs S.R.L.
    http://www.ritlabs.com/
    



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