RE: xsl processors turn off extension functions

> It's
> surprisingly
> common to find sites that are prepared to execute untrusted stylesheets,
> which can cause arbitrary havoc if extension functions are not disabled.
> Even with extension functions disabled, there's a denial-of-service risk.
I think also in light of GRDDL http://www.w3.org/2004/01/rdxh/spec that it is
even more important. Of course GRDDL suffers under some other security problems
as well.