[LSD] Security vulnerability in SUN's Java Virtual Machine implementation Oct 23 2003 08:52PM
Last Stage of Delirium (contact lsd-pl net) (1 replies)
Re: [LSD] Security vulnerability in SUN's Java Virtual Machine implementation Oct 28 2003 09:32AM
Alla Bezroutchko (alla scanit be) (1 replies)

Last Stage of Delirium wrote:
> Hello,
> We have found a security vulnerability in the SUN's implementation of the Java
> Virtual Machine, which affects the following SDK and JRE releases:
> - SDK and JRE 1.4.1_03 and earlier
> - SDK and JRE 1.3.1_08 and earlier
> - SDK and JRE 1.2.2_015 and earlier.

The following applet tests for this vulnerability:

import java.applet.Applet;
import java.awt.Graphics;
import java.lang.Class;
import java.security.AccessControlException;

public class Simple extends Applet {

StringBuffer buffer;

public void init() {
buffer = new StringBuffer();

public void start() {
ClassLoader cl = this.getClass().getClassLoader();
try {
Class cla =
cl.loadClass("sun/applet/AppletClassLoader"); // Note the slashes
addItem("No exception in loadClass. Vulnerable!");
} catch (ClassNotFoundException e) {
addItem("ClassNotFoundException in loadClass - " + e);
} catch (AccessControlException e) {
addItem("AccessControlException in loadClass - Not


void addItem(String newWord) {

public void paint(Graphics g) {
//Draw a Rectangle around the applet's display area.
g.drawRect(0, 0, size().width - 1, size().height - 1);

//Draw the current string inside the rectangle.
g.drawString(buffer.toString(), 5, 15);

This test can be found here: http://bcheck.scanit.be/bcheck/applet.html

If Sun Java VM is installed, the applet runs and says if VM is
vulnerable or not.

I am loading sun.applet.AppletClassLoader, but it could be any other
class from sun. package tree.

I don't know how this bug is exploitable, because whenever I try to do
anything at all with a class loaded this way, for example, create an
instance of it or call methods, I get SecurityManager's exceptions.
Gotta wait patiently until LSD releases more details.

I've tested Internet Explorer 6 and Mozilla Firebird. Internet Explorer
is exploitable if confgured to use Sun Java VM instead of Microsoft VM.


[ reply ]
Re: [LSD] Security vulnerability in SUN's Java Virtual Machine implementation Oct 27 2003 08:44PM
Marc Schoenefeld (schonef uni-muenster de)


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