Exploit failed: NoMethodError undefined method `gsub' for #<URI::Generic:0xc6006a8 URL:/> help

[syed]

I am trying to exploit CVE-2012-1823 using metasploit exploit exploit/multi/http/php_cgi_arg_injection.as soon i try to exploit i get an error : Exploit failed: NoMethodError undefined method `gsub' for #<URI::Generic:0xc6006a8 URL:/>

please help!!!