[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [WEB SECURITY] RE: XSS-Phishing on Financial Sites (Tip of the iceberg)




A few weeks ago I wrote about this on the blog: http://ha.ckers.org/blog/20060601/content-restrictions-and-xss/

Content restrictions are something Firefox has looked at, but are
lacking the development staff to build.  I'm sure they'd appreciate the
help if someone wanted to spend some time building it out, but for the
time being, there are no efforts I am aware of, other than IE appears to
be breaking the JavaScript directive inside of images (which definitely
won't solve the issue, but will close one vector).

-RSnake
http://ha.ckers.org/
http://ha.ckers.org/xss.html
http://ha.ckers.org/blog/feed/

On Sat, 24 Jun 2006, Brian Eaton wrote:

On 6/24/06, arian.evans <arian.evans@xxxxxxxxxxxxxx> wrote:
Most home DSL/cable/Router-thingies have changed from GETs to POSTs,
that I've looked at, but some POSTable forms still parse GET anyway
(maintaining trivially high attack surface).

Switching to POST doesn't do anything to prevent CSRF, at least not while nearly everybody uses browsers with javascript enabled.

<body onload="javascript:document.myform.submit()">

This year we released a homegrown WAF at BH Amsterdam to transparently
block these types of attacks, and were *really* excited about it.
It was poorly received and I think poorly understood, as I mentioned
before, due to presentation deficiencies.

Even if you don't work on this WAF any further, I think you should keep pitching the technique you were using to block XSS and CSRF. XSS and CSRF are epidemic, and most of the suggestions for resolving them are just picking around the edges of the problem. More comprehensive solutions are needed.

I've been wondering whether web application developers could cooperate
with browser vendors to find a way to make XSS and CSRF harder to
exploit.  I'm pretty sure that there is nothing a browser can do to
prevent exploitation of persistent XSS/CSRF vulnerabilities, but for
the more common "legitimate user visits malicious web site" scenarios
I suspect browsers could help.

Regards,
Brian

----------------------------------------------------------------------------
The Web Security Mailing List: http://www.webappsec.org/lists/websecurity/


The Web Security Mailing List Archives: http://www.webappsec.org/lists/websecurity/archive/
http://www.webappsec.org/rss/websecurity.rss [RSS Feed]




Brought to you by http://www.webappsec.org
Search this site