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The entire message "RE: Preventing cross site scripting", originally sent to you by Mutallip Ablimit (mutax () insi co 
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> --- Begin Message ---
>
>
> From: "Mutallip Ablimit" <mutax () insi co jp>
>
> Date: Fri, 20 Jun 2003 11:16:43 +0900
>
> Yes, replace all of the unacceptable tags with "", it will work fine.
> And for a plus,
> PHP has a strip_tags() function.
> Didn't have tried yet, but I think it could be used to remove all
> unacceptable tags.
> In this case, may be you have to make a list of all allowed tags.
>
> strip_tags($Text, "<allowed tag>");
>
> This will only allows the "<allowed tag>".
>
> Regards,
>
> -----------
> Mutellip Ablimit
> INSI
> mutax () insi co jp
>
> -----Original Message-----
> From: David Cameron [mailto:dcameron () itis-now com]
> Sent: Friday, June 20, 2003 10:51 AM
> To: Andrew Beverley; webappsec () securityfocus com
> Subject: RE: Preventing cross site scripting
>
>
> Create a list of unacceptable tags in an array (eg applet, embed), loop
> through the array and generate a regexpr based on the array, something of
> the form:
> <(applet)|(embed).?> and replace all instances with "".
>
> Do the same for any possible closing tags ie:
> </(applet)|(embed)> and replace all instances with "".
>
> BTW the RegExpr may be wrong, I'm not all that hot on RegExprs, but you get
> the idea.
>
> regards
> David Cameron
> nOw.b2b
> dcameron () itis-now com
>
> > -----Original Message-----
> > From: Andrew Beverley [mailto:mail () andybev com]
> > Sent: Friday, 20 June 2003 4:28 AM
> > To: webappsec () securityfocus com
> > Subject: Preventing cross site scripting
> >
> >
> > I am currently writing a web application that, as a small part of it,
> > needs to display an email message. Obviously the message is
> > potentially
> > in html format, which to display could be sent straight to
> > the browser.
> >
> > I would like to know the best way of filtering out undesirable html. I
> > understand the best way is to only allow acceptable
> > information, in this
> > case all the different html formatting tags.
> >
> > However, there is a lot of tags that are acceptable. Another approach
> > would be to strip out all the bad stuff such as <SCRIPT>, <OBJECT>,
> > <APPLET>, and <EMBED> but this is far from ideal because of new tags
> > becoming available and so on.
> >
> > Are there any functions available (for php) that will take a html page
> > as input and strip out all nasty stuff? Does anyone have
> > suggestions as
> > to how to do this as easy as possible?
> >
> > Thanks,
> >
> > Andrew Beverley
>
>
>
> --- End Message ---