Re: Cisco PIX Firewall MailGuard Vulnerability

From: Fabio Pietrosanti (naif) (naifat_private)
Date: Wed Sep 26 2001 - 18:47:05 PDT

  • Next message: Jerome Tytgat: "RE: Cisco PIX Firewall MailGuard Vulnerability"

    Hi Jerome,
    
    this vulnerability was posted on bugtraq several month by me, and i worked
    with cisco trying their fixed version and they released the new release of pix .
    
    Now Cisco talk about another way to bypass SMTP content filtering, that's not
    the way i disocovered many month ago, i suppose.
    
    The new advisory it's dated 2001 September 26, look @ Bugtraq the official
    e-mail from cisco, because on the website this is not updated .
    
    Regards
    
    On Tue, Sep 25, 2001 at 02:42:01PM +0200, Jerome Tytgat wrote:
    > rather outdated... 10-5-2000...
    > 
    > All recents - "less than one year" - binary
    > are ok (>4.4.7, 5.1.4, 5.2.3, 5.3.1, 6.0.1).
    > 
    > in fact the order of commands was not checked
    > (you could send a DATA before a RCPT TO).
    > 
    > And after sending a DATA command, command was not
    > checked anymore.
    > 
    > Simply send a DATA just after a HELO is refused by
    > the mail server with a 500 error but the pix saws 
    > the DATA command and is not checking anymore commands.
    > 
    > So the mailserver was vulnerable against attack if it has
    > bug (such as overflow).
    > 
    > The SMTP fixup is here to prevent use of some functions
    > like EXPN, VRFY.
    > 
    > _______________________________________________________________
    > ENERGIS
    > Jerome Tytgat
    > Network and Security Administrator
    > mailto:j.tytgatat_private        http://www.energis.fr
    > tel : (33) 03 88 78 77 77       2, rue paul Rohmer
    > fax : (33) 03 88 78 80 00       F-67087 Strasbourg Cedex 2
    > _______________________________________________________________
    > 
    >  
    > 
    > 
    > 
    > 
    > 
    > 
    > > -----Message d'origine-----
    > > De : Fabio Pietrosanti (naif) [mailto:naifat_private]
    > > Envoye : mardi 25 septembre 2001 12:06
    > > A : vuln-devat_private
    > > Objet : Cisco PIX Firewall MailGuard Vulnerability
    > > 
    > > 
    > > Hi,
    > > 
    > > i have received the advisory from cisco about the vulnerability 
    > > in the subject
    > > described here:
    > > http://www.cisco.com/warp/public/707/PIXfirewallSMTPfilter-pub.shtml
    > > 
    > > I discovered the old mailguard vulnerability, and i would like to know if
    > > someone could explain in details about this new kind of attack 
    > > against SMTP
    > > filter .
    > > 
    > > Regards
    > > 
    > > -- 
    > > 
    > > Fabio Pietrosanti ( naif )
    > > E-mail: naifat_private - naifat_private
    > > PGP Key (DSS) http://naif.itapac.net/naif.asc
    > > --
    > > Free advertising: www.openbsd.org Multiplatform Ultra-secure OS
    > > Free Flame: IPFilter sucks ! 
    > > 
    
    -- 
    
    Fabio Pietrosanti ( naif )
    E-mail: naifat_private - naifat_private
    PGP Key (DSS) http://naif.itapac.net/naif.asc
    --
    Free advertising: www.openbsd.org Multiplatform Ultra-secure OS
    Free Flame: IPFilter sucks ! 
    



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