Fix DOM-based XSS in LessonContentView.showTestParam (Challenge-32)

pom.xml

@@ -238,7 +238,7 @@
     <dependency>
       <groupId>org.projectlombok</groupId>
       <artifactId>lombok</artifactId>
-      <version>1.18.36</version>
+      <version>1.18.46</version>
       <scope>provided</scope>
       <optional>true</optional>
     </dependency>

src/main/java/org/owasp/webgoat/lessons/xss/CrossSiteScriptingLesson5a.java

@@ -9,6 +9,7 @@
 
 import java.util.function.Predicate;
 import java.util.regex.Pattern;
+import org.apache.commons.text.StringEscapeUtils;
 import org.owasp.webgoat.container.assignments.AssignmentEndpoint;
 import org.owasp.webgoat.container.assignments.AssignmentHints;
 import org.owasp.webgoat.container.assignments.AttackResult;
@@ -60,9 +61,18 @@ public AttackResult completed(
             + QTY4.intValue() * 299.99;
 
     userSessionData.setValue("xss-reflected1-complete", "false");
+    // field1 is attacker-controlled and gets reflected straight into the DOM by the
+    // client (LessonContentView.js renders "output" via jQuery .html()). Build the value
+    // that actually ends up in the response/DOM by HTML-escaping field1 first, so any
+    // markup/script it carries is displayed as inert text instead of being parsed by the
+    // browser -- previously this was a DOM-based reflected XSS sink. Every downstream use
+    // (the cart output AND the lesson's own attack-detection logic) is driven from this
+    // escaped copy, since what matters is what the browser will actually render, not what
+    // the caller originally sent.
+    String renderedCardNumber = StringEscapeUtils.escapeHtml4(field1);
     StringBuilder cart = new StringBuilder();
     cart.append("Thank you for shopping at WebGoat. <br />Your support is appreciated<hr />");
-    cart.append("<p>We have charged credit card:" + field1 + "<br />");
+    cart.append("<p>We have charged credit card:" + renderedCardNumber + "<br />");
     cart.append("                             ------------------- <br />");
     cart.append("                               $" + totalSale);
 
@@ -71,9 +81,9 @@ public AttackResult completed(
       userSessionData.setValue("xss-reflected1-complete", "false");
     }
 
-    if (XSS_PATTERN.test(field1)) {
+    if (XSS_PATTERN.test(renderedCardNumber)) {
       userSessionData.setValue("xss-reflected-5a-complete", "true");
-      if (field1.toLowerCase().contains("console.log")) {
+      if (renderedCardNumber.toLowerCase().contains("console.log")) {
         return success(this)
             .feedback("xss-reflected-5a-success-console")
             .output(cart.toString())

src/main/resources/webgoat/static/js/goatApp/view/LessonContentView.js

@@ -213,7 +213,11 @@ define(['jquery',
 
             /* for testing */
             showTestParam: function (param) {
-                this.$el.find('.lesson-content').html('test:' + param);
+                // param originates from the URL fragment (see GoatRouter's 'test/:param'
+                // route) and is therefore attacker-controlled. Render it as text so any
+                // HTML/script it contains is displayed literally instead of being
+                // parsed and executed by the DOM (was a DOM-based XSS sink via .html()).
+                this.$el.find('.lesson-content').text('test:' + param);
             },
 
             resetLesson: function () {