Shaun Mccran

My digital playground

02
M
A
R
2010

Changing the 404 template handler in IIS

You could use a 404 ColdFusion template to handle missing templates, or the onmissingtemplate Application CFC function. Luckily I have a client with half a dozen sites all on the same server, with nothing else on it, so it makes more sense to do this in Internet Information Services.

404 templates are a handy way of masking any site errors or missing templates. Not only are they a cosmetic fix to nasty display errors but they can also seriously help your server security.

[ More ]

20
J
A
N
2010

Internet dating disasters site - Online fraud and security

A popular daytime television show in the UK has recently broadcast an article on Internet security and Internet dating. With Online Dating being an industry I worked in for a brief period this was quite relevant to me.

http://www.itv.com/lifestyle/thismorning/more/internetdatingdisasters/

The main aim of the Sally Cornock's site is to warn of 'love rats' and suspicious profiles online. It appears that she was stung by a serial dater online and has done something about it.

It highlights the dilemma of free to join, fixed cost membership sites quite well though. Most dating sites are free to join. They provide very little functionality, and no interaction at all with other members UNLESS you upgrade your account and pay a fee. When you understand this it makes policing this near on impossible.

Sally Cornock has raised the issue of potentially having a governing body to perform validation on members as they join, so that you know someone is who they say they are. This would discourage a massive percentage of the market, as signing up for free by providing only one or two fields of data is simple. But passing an online verification is an extra level of hassle to the "casual shopper", which most people are. When you look at the statistics only a tiny number of signups ever convert to full membership.

It nicely highlights some of the less technical aspects of web usage, click through below to read more:

http://www.crimestoppers-uk.org/crime-prevention/helping-prevent-crime/personal-safety/online-dating-safety

http://www.e-victims.org/

http://www.suzylamplugh.org/personal-safety/personal-safety-tips/safety-on-the-internet/

http://www.victimsupport.org.uk/help%20for%20victims/Get%20information%20victims/Information%20about%20specific%20crimes/Cyber%20crime

22
D
E
C
2009

Using Isapi / Apache rewriting to mask URL strings, for cosmetics and security

One of the more recent additions to my Coldfusion frameworks is masking the more ugly URL's using Isapi rewrite. In this article I'll be using Helicon's Isapi ReWrite, but Apache re write works in much the same way.

Usually in your Coldfusion frameworks, most other technologies as well, you are passing around a variable or two to control the page content, and more often than not it is in the url. It never looks particularly clean if your URL has a long name value query string behind it, like this:

view plain print about
1http://www.mysite.com/index.cfm?variable1=pagename&location=england&value=7

Cosmetic reasons

So for two reasons URL rewriting seems like a good idea.

Firstly to mask those ugly URLS with a url rewriter. On a basic level this will re write specified request to the URL you tell it to, taking your ugly list of name value pairs and changing it into a user friend URL. If you are pitching this to a client this looks a lot more professional.

Security reasons

Secondly there is an added security benefit here. The URL gives a lot away about a website, like what the code base is, and is potentially a window on the internal workings of a website. Take a normal FuseBox application for example. The normal URL might be:

view plain print about
1www.mysite.com/index.cfm?fuseaction=controller.action&othervalues=values

From here it is very easy to start messing around with the controller names, trying to dig out an 'admin' controller, or other common function controller. Similarly adding values to pages where it is obvious a Query has been fired is an easy way of testing of the developer is using 'cfQueryParam', with potentially disastrous results.

Along the same lines it is quite simple to inject form values into the URL (like this http://www.mccran.co.uk/index.cfm/2009/7/30/Cross-site-Script-hacking-using-the-GET-method). By masking the URL and the values you make it considerably more difficult to do this, after all if you can see or get to the URL, how can you fool around with it?

So far I am implementing a rewrite script that will rewrite URLs into friendly strings, here is a modified version of the .htaccess file I'm using.

view plain print about
1# Helicon ISAPI_Rewrite configuration file
2# Version 3.1.0.68
3
4RewriteEngine on
5RewriteBase /wwwroot/
6
7#generic
8RewriteRule requestID/(.*)/(.*)/ index.cfm?decryptURL=$1&params=$2
9
10# site pages
11RewriteRule home(/)? index.cfm?go=controller.home
12RewriteRule contact(/)? index.cfm?go=controller.contact
13RewriteRule login(/)? index.cfm?go=controller.login
14RewriteRule privacy(/)? index.cfm?go=controller.privacy
15RewriteRule about(/)? index.cfm?go=controller.about
16RewriteRule faqs(/)? index.cfm?go=controller.faqs
17RewriteRule search(/)? index.cfm?go=controller.search

This code starts off by turning the rewriteEngine on, then setting the rewriteBase, this is typically your webroot, or the root of the site the file is for. Then it rewrites any URL params to the URL string.

The main part of the code is where we set individual rewriteRule's for each URL. The first example (home) looks for any URL requests to the 'home' string, and re writes this to the URL in the regular expression (index.cfm?go=controller.home). Pretty straight forward really.

There is a lot more you can do with this, and hopefully I'll get to explore rewriting in more depth in the future.

30
J
U
L
2009

Cross site Script hacking using the GET method

I've dealt with Cross Site scripting (XSS) attacks before ( http://www.mccran.co.uk/index.cfm/2009/4/6/Cross-Site-scripting-hack-test-form), so I'm familiar with the principles involved. In this example there is a subtle difference.

In the example above the vulnerability was created by POSTING a text string through the form action. In this example we will examine a similar vulnerability using GET. IE we will simply pass the attacking string through the url of the form, setting the form field value in the traditional 'url?variable=N' way.

To demonstrate this create a simple form:

view plain print about
1<cfparam name="attributes.formValue" default="">
2
3<form>
4
5<input type="text" name="formValue" size="20" value="<cfoutput>#attributes.formValue#</cfoutput>">
6<input type="submit" name="Action" value="Send">
7
8</form>

Call your form in a browser. Now append on the end of that url the text string below.

?attributes.formValue==>"><%2Ftitle><%2Fiframe><%2Fscript><%2Fform><%2Ftd><%2Ftr>
<%2FIfRamE>

Reading through the string you'll notice that it is an Iframe constructor that is calling a url, in this case www.Google.com.

As the url is setting the value of 'attributes.formValue' this will be inserted into the form on the submit action. We are not posting it, so it will not be picked up by any custom POST action code.

One interesting point to mention here is that testing this in IE 8, it will actually be blocked by default, as it has detected that scripts are running over different domains.

So if you are in the habit of writing POST detection scripts, make sure you handle any other submissions as well!

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