Re: [fw-wiz] HTML Emails and Firewall Security

From: Paul Robertson (proberts_at_patriot.net)
Date: 07/31/03

  • Next message: Paul Robertson: "Re: [fw-wiz] OT: Av and Gartner..."
    To: Ron Suarez <rsuarez@videotron.ca>
    Date: Wed, 30 Jul 2003 20:54:33 -0400 (EDT)
    
    

    On Wed, 30 Jul 2003, Ron Suarez wrote:

    > Hi all,
    >
    > I've been reading that HTML email can compromise network security. Because

    Well, to be more accurate, bugs in applications that handle HTML can be
    used to compromise network security.

    > if this, some companies filter out html email. Even Microsoft has decided to
    > disable the HTML function in the default installation of upcoming versions
    > of Microsoft Outlook.

    That's interesting, I hadn't heard that, but I applaud it wholeheartedly.

    >
    > I'm curious how many of you also see this as a threat to your network and
    > also filter out html emails?

    I've seen a few products that do that, I've had things in place ready to
    do that if there was an immediate threat, but haven't seen it necessary to
    do so.

    > I am also seeing more and more B2B marketing departments send html email
    > (eNewsletters) as part of their strategy. I'm thinking that their emails
    > aren't being received properly by their clients or received at all.

    Better than 90% of the spam I get is HTML, I've considered bouncing it
    automatically from the list too.

    > What are your thoughts?

    HTML is fine for Web pages, but the parsing of it, along with the active
    content payload makes it dangerous. I wouldn't actively block it, but I'd
    consider actively breaking it (I've run the old FWTK proxy with the
    Hitachi patches for active stuff for Web browsing) - I don't think there's
    much that you lose by removing all the tags or changing them to comments.

    It's not allowd on the list because of the concerns about active content
    embedded within it more than anything (and it's annoying if you don't use
    an HTML-enabled mail client.)

    Paul
    -----------------------------------------------------------------------------
    Paul D. Robertson "My statements in this message are personal opinions
    proberts@patriot.net which may have no basis whatsoever in fact."
    probertson@trusecure.com Director of Risk Assessment TruSecure Corporation

    _______________________________________________
    firewall-wizards mailing list
    firewall-wizards@honor.icsalabs.com
    http://honor.icsalabs.com/mailman/listinfo/firewall-wizards


  • Next message: Paul Robertson: "Re: [fw-wiz] OT: Av and Gartner..."

    Relevant Pages

    • Re: Saving aspx to file or other solution
      ... Roland, I mangaed to try your way, I did managed to snapshot the Form ... Then when the user submits it, we need to send an HTML email to the ... HTML produced by the ASP page; paste into the editor of your choice; prepend ... than we want to save this page to a Database ...
      (microsoft.public.dotnet.framework.aspnet)
    • Re: Saving aspx to file or other solution
      ... Thx alexy,Rolnad,Dave ... Then when the user submits it, we need to send an HTML email to the ... HTML produced by the ASP page; paste into the editor of your choice; prepend ... than we want to save this page to a Database ...
      (microsoft.public.dotnet.framework.aspnet)
    • Re: Searching!!
      ... Most Posters in Newsgroups use Plain Text Not (HTML). ... HTML email contains commands to be executed by your email client: ... these commands can be used maliciously to exploit common security holes. ... opens up using Google as the search engine. ...
      (microsoft.public.windows.inetexplorer.ie6.browser)
    • Re: HTML email "bug", of sorts.
      ... HTML email "bug", of sorts. ... I never took the time to look through the HTML code of e-mails that I ... I've started seeing web bugs. ...
      (Bugtraq)
    • Re: Saving aspx to file or other solution
      ... Then when the user submits it, we need to send an HTML email to the ... HTML produced by the ASP page; paste into the editor of your choice; prepend ... than we want to save this page to a Database ... any ideas how to save the aspx with user data to file? ...
      (microsoft.public.dotnet.framework.aspnet)