Disable use of iframes in firefox

<yambe:breadcrumb>Security_tips|Security tips</yambe:breadcrumb>

Disable use of iFrames in firefox

It is very common to use iFrames for attacks, but legitimate use of iFrames is still very rare. Hence one can block iFrames completely to increase security at cost of minor inconvenience in visiting few websites which can then be created exception for or visited using another browser. To block iFrames in firefox use:

1. Go to firefox profiles folder. In Linux profile folder is inside ~/.mozilla folder. Further profile folder name has pattern *.default.
2. Create a folder named chrome, if it does not exists. (Yes name of folder is chrome and it has most likely nothing to do with Chrome browser)
3. Create a file named userContent.css, if it does not exists.
4. Add following configuration to userContent.css file:

   iframe {
   display: none !important;
   }

5. Restart firefox and try to visit http://www.w3schools.com/tags/tryit.asp?filename=tryhtml_iframe page to see if iframe is still visible or not.