fix: rename struct2 -> struts2

vul/vul-struts2/src/main/java/Base64ClassLoaderAction.java

@@ -0,0 +1,52 @@
+import com.opensymphony.xwork2.ActionSupport;
+import org.apache.struts2.ServletActionContext;
+
+import java.lang.reflect.Method;
+import java.net.URL;
+import java.net.URLClassLoader;
+
+/**
+ * @author ReaJason
+ * @since 2024/12/24
+ */
+public class Base64ClassLoaderAction extends ActionSupport {
+
+    private String data;
+
+    static byte[] decodeBase64(String base64Str) throws Exception {
+        try {
+            Class<?> decoderClass = Class.forName("sun.misc.BASE64Decoder");
+            return (byte[]) decoderClass.getMethod("decodeBuffer", String.class).invoke(decoderClass.newInstance(), base64Str);
+        } catch (Exception var4) {
+            Class<?> decoderClass = Class.forName("java.util.Base64");
+            Object decoder = decoderClass.getMethod("getDecoder").invoke((Object) null);
+            return (byte[]) decoder.getClass().getMethod("decode", String.class).invoke(decoder, base64Str);
+        }
+    }
+
+    public Class<?> reflectionDefineClass(byte[] classBytes) throws Exception {
+        URLClassLoader urlClassLoader = new URLClassLoader(new URL[0], Thread.currentThread().getContextClassLoader());
+        Method defMethod = ClassLoader.class.getDeclaredMethod("defineClass", byte[].class, Integer.TYPE, Integer.TYPE);
+        defMethod.setAccessible(true);
+        return (Class<?>) defMethod.invoke(urlClassLoader, classBytes, 0, classBytes.length);
+    }
+
+    public String execute() throws Exception {
+        try {
+            byte[] bytes = decodeBase64(data);
+            Object obj = reflectionDefineClass(bytes).newInstance();
+            ServletActionContext.getResponse().getWriter().print(obj);
+            return null;
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public String getData() {
+        return data;
+    }
+
+    public void setData(String data) {
+        this.data = data;
+    }
+}