Home page logo
/

fulldisclosure logo Full Disclosure mailing list archives

Re: Rails and redirections
From: Brandon Perry <bperry.volatile () gmail com>
Date: Thu, 6 Mar 2014 19:23:17 -0600

FWIW this particular line has been present since early 2012.

f52ad6cf actionpack/lib/action_controller/metal/redirecting.rb   (Aaron
Patterson           2012-03-15 14:56:50 -0700 106)
end.gsub(/[\0\r\n]/, '')


On Thu, Mar 6, 2014 at 7:11 PM, Brandon Perry <bperry.volatile () gmail com>wrote:

I agree, an exception is the correct behavior.


On Thu, Mar 6, 2014 at 2:10 PM, Timothy Goddard <tim () goddard net nz>wrote:

Very interesting, could cause issues. It can't use the value and not
substitute - that's worse. Have seen response splitting in mod_perl because
it outputs raw strings in to location headers. In my view it should raise
an exception if not a valid URI.


Sent from Samsung Mobile



-------- Original message --------
From: Brandon Perry <bperry.volatile () gmail com>
Date:
To: full-disclosure () lists grok org uk
Subject: [Full-disclosure] Rails and redirections



Currently, passing \0, \r, or \n into a URL that is passed to redirect_to
has Rails gsub'ing them out of the URL before completing the redirect.

A programmer that doesn't realise this is happening could easily write a
regex and logic that says "if url starts with https:// or http:// fail
or else redirect_to url".

Seems straighforward, but an attacker could simply pass in a url like
\nhttp://www.google.com and bypass the regex check and be redirected to
google.com.

The line effecting this is line 106 in redirecting.rb in Rails.


https://github.com/rails/rails/blob/3-2-stable/actionpack/lib/action_controller/metal/redirecting.rb#L106

I feel like this is something that Rails should not be doing on behalf of
the programmer. The programmer should be expected to pass in exactly what
they want redirected to without Rails changing their data. Should this be
considered a vulnerability?

Thoughts?

--
http://volatile-minds.blogspot.com -- blog
http://www.volatileminds.net -- website




--
http://volatile-minds.blogspot.com -- blog
http://www.volatileminds.net -- website




-- 
http://volatile-minds.blogspot.com -- blog
http://www.volatileminds.net -- website
_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]
AlienVault