Added CSV separator validation

Author: momo3404

app/controllers/usage_controller.rb

@@ -151,9 +151,14 @@ def parse_filtered
     params[:filtered].present? && params[:filtered] == 'true'
   end
 
-  # set the csv separator or default to comma
+  # This sets the csv separator
+  # Ensures separator is either a comma or a safe separator
   def sep_param
-    params['sep'] || ','
+    safe_csv_separators = Rails.configuration.x.application.csv_separators
+    sep = params['sep'].to_s
+    return sep if safe_csv_separators.include?(sep)
+
+    ','
   end
 
   def min_max_dates(args:)