feat: add product controller

ProductController.java

@@ -0,0 +1,40 @@
+package com.corp.catalog;
+
+import java.beans.XMLDecoder;
+import java.io.ByteArrayInputStream;
+
+import org.springframework.expression.Expression;
+import org.springframework.expression.ExpressionParser;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.web.bind.annotation.*;
+
+@RestController
+public class ProductController {
+
+    // VULN 1: SpEL Injection — a user-supplied string is parsed and evaluated as
+    // a Spring Expression, giving arbitrary Java execution (RCE).
+    @GetMapping("/filter")
+    public String filter(@RequestParam String q) {
+        ExpressionParser parser = new SpelExpressionParser();
+        Expression exp = parser.parseExpression(q); // ?q=T(java.lang.Runtime).getRuntime().exec("id")
+        return String.valueOf(exp.getValue());
+    }
+
+    // VULN 2: XML Injection — user values are concatenated into an XML document
+    // without encoding, so input can inject or alter elements consumed
+    // downstream as trusted XML.
+    @PostMapping("/order")
+    public String order(@RequestParam String item, @RequestParam String qty) {
+        String xml = "<order><item>" + item + "</item><qty>" + qty + "</qty></order>";
+        return xml;
+    }
+
+    // VULN 3: Insecure Deserialization via XMLDecoder — decodes attacker-supplied
+    // XML into live objects, a well-known Java RCE sink.
+    @PostMapping("/import")
+    public String importData(@RequestBody byte[] body) {
+        XMLDecoder dec = new XMLDecoder(new ByteArrayInputStream(body));
+        Object o = dec.readObject(); // RCE
+        return "imported: " + o;
+    }
+}