A critical vulnerability (CVE-2023-21934) has been discovered in the Java Virtual Machine (Java VM) component of Oracle Database Server. The vulnerability affects supported versions 19c and 21c, and if successfully exploited, it can lead to unauthorized access to critical data and the ability to create, delete, or modify information stored in the Java VM. This article discusses the specifics of the vulnerability, including the exploit details, related code snippet, and links to original references.

Exploit Details

The vulnerability is difficult to exploit, requiring a low-privileged attacker with user account privileges and network access via TLS. However, if successful, the attacker can compromise the Java VM and gain unauthorized access to critical data or complete access to all Java VM accessible data.

The Common Vulnerability Scoring System (CVSS) 3.1 Base Score for this vulnerability is 6.8, indicating Confidentiality and Integrity impacts. The CVSS Vector is: (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N).

Code Snippet

import java.io.*;
import java.net.Socket;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;

public class CVE_2023_21934_Exploit {
    public static void main(String[] args) {
        String host = "vulnerable_host";
        int port = 1521;
        try {
            // Establish a secure connection via TLS.
            SSLSocketFactory sslSocketFactory = (SSLSocketFactory) SSLSocketFactory.getDefault();
            SSLSocket sslSocket = (SSLSocket) sslSocketFactory.createSocket(host, port);
            // Perform malicious actions on the Java VM component of Oracle Database Server.
            // ... Exploit code ...
            // Close the connection.
            sslSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

This code snippet demonstrates how an attacker can establish a connection to a vulnerable Oracle Database Server using TLS. The actual exploit code to execute malicious actions on the Java VM component is not provided to deter malicious usage.

Original References

The vulnerability was first reported by Oracle as part of their Critical Patch Update for October 2021. The official CVE entry can be found in the CVE List.

Mitigation

Oracle has released patches for the affected versions, which can be downloaded from the Oracle Critical Patch Update Advisory. Users are advised to apply the appropriate security patches as soon as possible to protect their systems from potential attacks.

Conclusion

The CVE-2023-21934 vulnerability in the Java VM component of Oracle Database Server is a severe issue that can lead to unauthorized access to critical data and the ability to create, delete, or modify Java VM accessible data. It is crucial for organizations using Oracle Database Server versions 19c and 21c to be aware of this vulnerability and take the necessary steps to secure their systems. Patch your systems immediately and always keep up to date with security updates and best practices.

Timeline

Published on: 04/18/2023 20:15:00 UTC
Last modified on: 04/19/2023 14:32:00 UTC