CVE-2023-21954 - Critical Vulnerability in Oracle Java SE and Oracle GraalVM Enterprise Edition, Allowing Unauthorized Access to Critical Data

Summary: A difficult to exploit vulnerability has been discovered in Oracle Java SE and Oracle GraalVM Enterprise Edition, which could allow unauthenticated attackers with network access to compromise the system and gain unauthorized access to critical data. This vulnerability affects supported versions Oracle Java SE: 8u361, 8u361-perf, 11..18, 17..6; Oracle GraalVM Enterprise Edition: 20.3.9, 21.3.5 and 22.3.1. The CVSS 3.1 Base Score is 5.9.

Introduction: The CVE-2023-21954 vulnerability exists in the Oracle Java SE, Oracle GraalVVM Enterprise Edition product of Oracle Java SE (component: Hotspot). This vulnerability primarily impacts Java deployments that run sandboxed Java Web Start applications or sandboxed Java applets, loading and executing untrusted code (e.g., code from the Internet) relying on the Java sandbox for security. The vulnerability can also be exploited by using APIs in the specified component, for instance, through a web service providing data to the APIs.

Exploit Details: While the exact details of an exploit leveraging this vulnerability are unknown, it would likely involve an attacker crafting malicious untrusted code or data to exploit the weakness in the Hotspot component of Oracle Java SE and Oracle GraalVM Enterprise Edition. By successfully exploiting this vulnerability, an attacker could gain unauthorized access to critical data or complete access to all accessible data in Oracle Java SE and Oracle GraalVM Enterprise Edition.

The associated CVSS Vector for this vulnerability is (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N), indicating that the vulnerability is exploitable via network access, requires a high level of attack complexity, does not require user privileges or interaction, and impact is limited to confidentiality.

Mitigation: Oracle has released security patches for the affected versions of Oracle Java SE and Oracle GraalVM Enterprise Edition to address this vulnerability. Users are strongly advised to apply the patches as soon as possible and follow best practices for secure Java deployment, such as running untrusted code only in a secure sandbox.

Original References

1. Oracle Security Alert for CVE-2023-21954: https://www.oracle.com/security-alerts/alert-CVE-2023-21954.html
2. CVSS 3.1 Scoring and Metrics: https://www.first.org/cvss/v3.1/specification-document

Code Snippet Example

While there is no specific code snippet available for exploiting this vulnerability, an example of a Java Web Start application that could potentially be targeted by an attacker is shown below.

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;

public class ExampleWebStartApp extends JFrame {

  public static void main(String[] args) {
    SwingUtilities.invokeLater(() -> new ExampleWebStartApp());
  }

  public ExampleWebStartApp() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    add(new JLabel("This is an example Java Web Start application."));
    pack();
    setLocationRelativeTo(null);
    setVisible(true);
  }
}

In conclusion, the CVE-2023-21954 vulnerability in Oracle Java SE and Oracle GraalVM Enterprise Edition poses a significant risk to systems running affected versions. By exploiting this vulnerability, attackers could potentially gain unauthorized access to sensitive data. It is vital for users to apply the security patches released by Oracle and follow best practices for secure Java deployment.

Timeline

Published on: 04/18/2023 20:15:00 UTC
Last modified on: 04/27/2023 15:15:00 UTC