A critical vulnerability, identified as CVE-2023-21839, has been discovered in the Oracle WebLogic Server product, which is a part of Oracle Fusion Middleware. The affected components include Core and supported versions,, and 14.1.1... Successful exploitation of this vulnerability could lead to unauthorized access to sensitive data or even complete access to all accessible data within the Oracle WebLogic Server.

The vulnerability can be exploited by an unauthenticated attacker with network access via T3 and IIOP channels. The CVSS (Common Vulnerability Scoring System) 3.1 Base Score for this vulnerability is 7.5, reflecting its potential impact on the confidentiality of the affected system. The full CVSS vector for this vulnerability is (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N).

Code Snippet

While explicit details about the exploit or a proof-of-concept are not available for ethical reasons, developers and system administrators can be vigilant in monitoring their systems for any suspicious activity on T3 and IIOP channels.

# Sample code to monitor T3 and IIOP channels
import logging
from java.lang import System
from weblogic.management.runtime import ExecuteThread

def monitor_channels():
    logging.info("Monitoring T3 and IIOP channels in Oracle WebLogic Server")

    if System.getProperty("weblogic.ListenPort") is not None:
        t3_port = int(System.getProperty("weblogic.ListenPort"))
    iiop_port = int(System.getProperty("weblogic.IIOPPort"))

    # Monitor for any suspicious connections on T3 and IIOP channels
    for thread in ExecuteThread.getThreads():
        connection = thread.getCurrentConnection()
        if connection:
            remote_address = connection.getRemoteAddress()
            if connection.getProtocol() in ['t3', 'iiop']:
                # Implement logic to check if the remote_address is suspicious
                is_suspicious = check_suspicious_address(remote_address)
                if is_suspicious:
                    logging.warning(f"Possible exploit attempt from {remote_address}")

def check_suspicious_address(address):
    # Check the address against known suspicious IPs or your preferred threat intelligence source
    return False

1. Oracle Critical Patch Update Advisory - October 2023
2. National Vulnerability Database NVD Entry
3. Oracle WebLogic Server Support Page

Exploit Details

At the time of writing, there are no publicly available exploit details or proof-of-concept code. Nonetheless, organizations using affected Oracle WebLogic Server versions,, and 14.1.1.. should urgently apply the necessary security patches and updates provided by Oracle. It is also essential to monitor network traffic for any attempts to exploit this vulnerability via the T3 and IIOP channels.  Strictly following security best practices, applying the principle of least privilege, and keeping the software up to date can help mitigate the risk posed by this vulnerability.

If you have any concerns regarding the CVE-2023-21839 vulnerability, it is highly recommended to get in touch with Oracle Support for assistance and further guidance on securing your WebLogic Server environment.


Published on: 01/18/2023 00:15:00 UTC
Last modified on: 01/24/2023 19:28:00 UTC