Re: "Strip Script Tags" in FW-1 can be circumvented

From: Arne Vidstrom (arne.vidstromat_private)
Date: Tue Feb 01 2000 - 10:19:25 PST

  • Next message: Michal Zalewski: "no comment"

    The reason to strip script tags would be to protect users from hostile code
    which the browsers can't handle themselves. Adding this feature to a
    firewall at all, but not making it work properly in all cases (probably a
    hopeless task anyway...) makes a false sense of security, which often is
    worse than no security at all.
    
    /Arne Vidstrom
    
    http://ntsecurity.nu
    
    
    > To: BugTraq
    > Subject: Re: "Strip Script Tags" in FW-1 can be circumvented
    > Date: Mon Jan 31 2000 00:28:29
    > Author: Jonah Kowall
    >
    > I don't consider this a bug in FW-1, but a bug in the products
    > navigator, and internet explorer.  These tags shouldn't be parsed, because
    > they are malformed.  The firewall is stripping tags properly, but since
    > these tags are malformed you can't expect the firewall to be able to
    > recognize them as valid tags.
    



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