Update oscommerce_installer_unauth_code_exec.rb

modules/exploits/multi/http/oscommerce_installer_unauth_code_exec.rb

@@ -51,7 +51,12 @@ class MetasploitModule < Msf::Exploit::Remote
       'method' => 'GET'
     })
 
-    if res and res.code == 200 and res.body.include?('Welcome to osCommerce Online Merchant v2.3.4!')
+    ins = send_request_cgi({
+      'uri'     => normalize_uri(datastore['URI'], 'install.php'),
+      'method' => 'GET'
+    })
+
+    if ins && ins.code == 200 && res && res.code == 200 && res.body.include?('Welcome to osCommerce Online Merchant')
       return CheckCode::Vulnerable
     end