RE: CSP and innerHTML

I'm interested in an example attack this would stop, which depends uniquely on inner/outerHTML.

The only use I can think of for this off the top of my head is if you're attempting to use a supervisory script to monitor and approve changes to the DOM  - which the implementation details of innerHTML typically do an end-run around.  Otherwise, isn't innerHTML functionally equivalent to other DOM-based APIs?  (and shouldn't the internal implementation be subject to the same CSP constraints already?)

-Brad

> -----Original Message-----
> From: Ian Melven [mailto:imelven@mozilla.com]
> Sent: Tuesday, April 30, 2013 11:08 AM
> To: WebAppSec WG
> Subject: CSP and innerHTML
> 
> 
> Hi,
> 
> recently Jonas Sicking raised the idea of having a CSP directive that would
> block usage of innerHTML
> 
> the primary motivation for doing this seems to be additional defence in
> depth on top of CSP already restricting script and style injections
> 
> i'm curious what others think of this idea and looking for feedback :)
> 
> thanks,
> ian