implement redirect check

app/controllers/ping_controller.rb

@@ -10,6 +10,10 @@ def index
     render json: { status: :ok }
   end
 
+  def pong
+    render json: { status: :ok }
+  end
+
   private
 
   def body

config/routes.rb

@@ -1,3 +1,4 @@
 API_Fuzzer::Engine.routes.draw do
   get '/ping/:id' => 'ping#index'
+  get '/ping' => 'ping#pong'
 end

lib/API_Fuzzer/redirect_check.rb

@@ -0,0 +1,103 @@
+require 'API_Fuzzer/vulnerability'
+require 'API_Fuzzer/error'
+require 'API_Fuzzer/request'
+require 'uri'
+
+module API_Fuzzer
+  class RedirectCheck
+    REDIRECT_URL = 'http://127.0.0.1:3000/ping'
+    ALLOWED_METHODS = [:get, :post]
+    class << self
+      def scan(options = {})
+        @url = options[:url]
+        @params = options[:params] || {}
+        @cookies = options[:cookies] || {}
+        @json = options[:json] || false
+
+        @vulnerabilities = []
+        fuzz_payload
+        return @vulnerabilities.uniq { |vuln| vuln.description }
+      rescue Exception => e
+        @vulnerabilities << API_Fuzzer::Error.new(
+          description: e.message,
+          status: 'ERROR',
+          value: e.backtrace
+        )
+      end
+
+      def fuzz_payload
+        uri = URI(@url)
+        path = uri.path
+        query = uri.query
+        # base_uri = query.nil? ? path : [path, query].join("?")
+        fragments = path.split(/[\/,?,&]/) - ['']
+        fragments << query.split('&')
+        fragments.flatten!
+        fragments.each do |fragment|
+          if fragment.match(/\A(\w+)=(.?*)\z/) && valid_url?($2)
+            url = @url.gsub($2, REDIRECT_URL).chomp
+            fuzz_fragment(url)
+          elsif valid_url?(fragment)
+            url = @url.gsub(fragment, REDIRECT_URL)
+            fuzz_fragment(url)
+          end
+        end
+        return if @params.empty?
+
+        @params.keys.each do |parameter|
+          fuzz_each_parameter(parameter) if valid_url? @params[parameter]
+        end
+      end
+
+      def fuzz_fragment(url)
+        ALLOWED_METHODS.each do |method|
+          begin
+            response = API_Fuzzer::Request.send_api_request(
+              url: url,
+              method: method,
+              cookies: @cookies,
+              params: @params
+            )
+
+            @vulnerabilities << API_Fuzzer::Vulnerability.new(
+              description: "Possible Open Redirect vulnerability in #{method} #{url}",
+              parameter: "URL: #{url}",
+              value: "[PAYLOAD] #{url.gsub(REDIRECT_URL, 'PAYLOAD_URL')}",
+              type: 'MEDIUM'
+            ) if response.headers['Location'] =~ /#{REDIRECT_URL}/
+          rescue Exception => e
+            puts e.message
+          end
+        end
+      end
+
+      def fuzz_each_parameter(parameter)
+        params = @params
+        params[parameter] = REDIRECT_URL
+        ALLOWED_METHODS.each do |method|
+          begin
+            response = API_Fuzzer::Request.send_api_request(
+              url: @url,
+              method: method,
+              cookies: @cookies,
+              params: params
+            )
+
+            @vulnerabilities << API_Fuzzer::Vulnerability.new(
+              description: "Possible Open Redirect vulnerability in #{method} #{url}",
+              parameter: "Parameter: #{parameter}",
+              value: "[PAYLOAD] #{params.to_s.gsub(REDIRECT_URL, 'PAYLOAD_URL')}",
+              type: 'MEDIUM'
+            ) if response.headers['LOCATION'] =~ /#{REDIRECT_URL}/
+          rescue Exception => e
+            puts e.message
+          end
+        end
+      end
+
+      def valid_url? url
+        url =~ URI.regexp
+      end
+    end
+  end
+end

lib/API_Fuzzer/sql_check.rb

@@ -70,7 +70,7 @@ def self.fuzz_each_fragment(url, payload)
             method: method,
             cookies: @cookies
           )
-          
+
           @vulnerabilities << API_Fuzzer::Error.new(description: "#{method} #{@url}", status: response.status, value: response.body) unless success?(response)
           body = ''
           if response_json?(response)