Bugtraq mailing list archives
Re: [LSD] Security vulnerability in SUN's Java Virtual Machine implementation
From: Alla Bezroutchko <alla () scanit be>
Date: Tue, 28 Oct 2003 10:32:07 +0100
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 Vulnerable!");
} } void addItem(String newWord) { System.out.println(newWord); buffer.append(newWord); repaint(); } 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.htmlIf 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.
Alla.
Current thread:
- [LSD] Security vulnerability in SUN's Java Virtual Machine implementation Last Stage of Delirium (Oct 23)
- Re: [LSD] Security vulnerability in SUN's Java Virtual Machine implementation Alla Bezroutchko (Oct 27)
- Re: [LSD] Security vulnerability in SUN's Java Virtual Machine implementation Marc Schoenefeld (Oct 27)
- Re: [LSD] Security vulnerability in SUN's Java Virtual Machine implementation Alla Bezroutchko (Oct 27)