CVE-2023-22052: Oracle Database Server Privilege Escalation

CVE-2023-22052 Overview

CVE-2023-22052 is a vulnerability in the Java VM component of Oracle Database Server that allows a low privileged attacker to perform unauthorized data modification. The vulnerability requires network access and specific database privileges to exploit, making it difficult to leverage in practice. However, successful exploitation can lead to unauthorized update, insert, or delete access to Java VM accessible data within the database environment.

Critical Impact

Attackers with Create Session and Create Procedure privileges can potentially modify Java VM accessible data through network-based attacks, compromising data integrity in affected Oracle Database Server deployments.

Affected Products

• Oracle Database Server versions 19.3 through 19.19
• Oracle Database Server versions 21.3 through 21.10

Discovery Timeline

• 2023-07-18 - CVE CVE-2023-22052 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-22052

Vulnerability Analysis

This vulnerability resides in the Java VM component of Oracle Database Server, which provides Java runtime capabilities within the database environment. The flaw enables a low-privileged attacker who has already obtained Create Session and Create Procedure privileges to potentially manipulate data accessible through the Java VM subsystem.

The attack complexity is high, indicating that successful exploitation requires specific conditions beyond just having network access and the required privileges. The vulnerability has integrity impacts only, meaning attackers cannot read confidential data or cause denial of service through this specific flaw. The unchanged scope indicates the vulnerability is contained within the Java VM component and does not allow attackers to pivot to other systems or components.

Root Cause

The root cause of this vulnerability has not been publicly disclosed by Oracle. Based on the component affected and the impact characteristics, the vulnerability likely stems from improper access control or validation within the Java VM component when handling certain operations from authenticated users with procedural privileges.

Attack Vector

The attack requires network access via multiple protocols to the Oracle Database Server. The attacker must possess at minimum Create Session and Create Procedure privileges on the target database. Given the high attack complexity, additional factors such as specific timing, environmental conditions, or particular configurations may be necessary for successful exploitation.

The network-based attack vector means the vulnerability can be exploited remotely, but the privilege requirements significantly limit the pool of potential attackers to those who already have authenticated access to the database with elevated privileges.

Detection Methods for CVE-2023-22052

Indicators of Compromise

• Unexpected modifications to data accessible through Java VM stored procedures
• Unusual activity from accounts with Create Session and Create Procedure privileges
• Anomalous Java VM operations or procedure executions in database audit logs

Detection Strategies

• Monitor Oracle Database audit logs for suspicious Java VM component activity
• Review and audit accounts with Create Session and Create Procedure privileges
• Implement database activity monitoring to detect unauthorized data modifications
• Enable fine-grained auditing on Java VM accessible objects and procedures

Monitoring Recommendations

• Configure Oracle Database auditing to capture all Java VM related operations
• Set up alerts for data modification operations from accounts with procedural privileges
• Regularly review database privilege assignments to identify over-privileged accounts
• Implement network monitoring to detect unusual connection patterns to database servers

How to Mitigate CVE-2023-22052

Immediate Actions Required

• Apply the Oracle Critical Patch Update (CPU) from July 2023 immediately
• Review and restrict Create Session and Create Procedure privileges to only essential accounts
• Audit existing user privileges and remove unnecessary procedural access
• Implement network segmentation to limit database server exposure

Patch Information

Oracle has released patches for this vulnerability as part of the July 2023 Critical Patch Update. Organizations should apply the appropriate patch for their Oracle Database Server version. Detailed patch information and download instructions are available in the Oracle Security Alert July 2023.

For Oracle Database Server 19c, update to version 19.20 or later. For Oracle Database Server 21c, update to version 21.11 or later.

Workarounds

• Restrict network access to Oracle Database Server through firewall rules and network ACLs
• Implement the principle of least privilege by reviewing and limiting Create Procedure grants
• Disable Java VM component if not required for business operations using DBMS_JAVA.REVOKE_PERMISSION
• Enable Oracle Database Vault to provide additional access control layers

# Example: Review users with Create Procedure privilege
sqlplus / as sysdba
SELECT grantee, privilege FROM dba_sys_privs WHERE privilege = 'CREATE PROCEDURE';

# Revoke unnecessary privileges
REVOKE CREATE PROCEDURE FROM unnecessary_user;