Who's got the last laugh now. The Blogger XSS Vulnerability

I guess I was asking for punishment. I go looking for Web App Vulnerabilities all over the world, and sure as hell, this is what I will get.

I discovered that once I posted my Rediff Search Engine XSS Vulnerability on Blogger, I noticed something I had seen all too often, the Javascript alert with the rudimentary XSS, and this time, it was on my blog. I was not to happy about it to say the least. I thought "Some Smart Alec must have written up a comment causing the XSS alert, but I was quite sure that couldnt happen because Blogger had some sort of a filter on the comments. I then realized that the XSS alerts were popping up because of the XSS vectors in my Rediff post.

Surprisingly Blogger does not do any kind of validation or output encoding to prevent against these attacks in the posts section. So the blog-author can potentially be serving up XSS on his/her blog and potentially be exposing all the visitor's accounts with that, and since Blogger is a Google service, my session credentials are good for any Google Website. Mail, docs, everything.

But its ok now folks, the bitter pill of my own medicine has been swallowed................ or has it?