diff --git a/src/main/java/utilities/UnZip.java b/src/main/java/utilities/UnZip.java
index fffa481..2014a9f 100644
--- a/src/main/java/utilities/UnZip.java
+++ b/src/main/java/utilities/UnZip.java
@@ -19,7 +19,10 @@ public static void unZip(String zippedFile, String outputFolder) {
             ze = zis.getNextEntry();
             while (ze != null) {
                 String fileName = ze.getName();
-                File newFile = new File(outputFolder + File.separator + fileName);
+                File newFile = new File(outputFolder, fileName);
+                if (!newFile.toPath().normalize().startsWith(outputFolder)) {
+                    throw new RuntimeException("Bad zip entry");
+                }
                 System.out.println("file unzip : " + newFile.getAbsoluteFile());
                 //create all non exists folders
                 //else you will hit FileNotFoundException for compressed folder