Tomcat Virtual Host to prevent Improper-Input-Handling attack

I'm currently on the process of trying fix a site vulnerability, basically it is one type of the "Improper Input Handling" attack.

Let's say my website is www.mywebsite.com and there is hacker's website www.hacker.com

whenever there is a request send to www.mywebsite.com with modified "Host" header point to www.hacker.com, my site will create a redirect to www.mywebsite.com along with whatever the url it was. e.g.

Normal:

Host: www.mywebsite.com 
GET  www.mywebsite.com/get/some/resources/
Reponse 200 ok

Hack:

Host: www.hacker.com (#been manually modified) 
GET  www.mywebsite.com/get/some/resources/
Response 302 
Send another Redirect to www.hacker.com/get/some/resources 

My website is running on Tomcat 7, I tried some solution with set up the virtual host by point the unknown host to a defaultlocalhost which suppose to do nothing. but it still send the redirect for some reason.

Here attached is my server.xml host configure:

<Engine name="Catalina" defaultHost="defaultlocalhost" jvmRoute="jvm1">  
<Host name="www.mywebsite.com"  appBase="webapps"
        unpackWARs="true" autoDeploy="false" deployOnStartup="true">

    <Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs"
           prefix="localhost_access_log." suffix=".txt"
           pattern="%h %l %u %t &quot;%r&quot; %s %b" />
  </Host>

  <Host name="defaultlocalhost"  >

  </Host>

So, my question is, Am I on the right track to prevent this kind of attack ? If yes, what I did wrong that still not working? (The ultimate goal is, if it is not the legit Host that been passed in, the request should be discard/ignored/return 404 but not redirect with 302)

Thank you in advance.

More references about the attack here : http://www.skeletonscribe.net/2013/05/practical-http-host-header-attacks.html

http://projects.webappsec.org/w/page/13246933/Improper%20Input%20Handling