CVE-2022-21511: Oracle Database Privilege Escalation Flaw

CVE-2022-21511 Overview

CVE-2022-21511 is a privilege escalation vulnerability in the Oracle Database - Enterprise Edition Recovery component of Oracle Database Server. This easily exploitable vulnerability allows a high privileged attacker with EXECUTE ON DBMS_IR.EXECUTESQLSCRIPT privilege and network access via Oracle Net to completely compromise the Oracle Database - Enterprise Edition Recovery component. Successful exploitation results in a full takeover of the affected component, impacting confidentiality, integrity, and availability.

Critical Impact

A privileged attacker can achieve complete takeover of the Oracle Database Enterprise Edition Recovery component, potentially compromising sensitive data and disrupting database availability.

Affected Products

• Oracle Database - Enterprise Edition
• Oracle Database Recovery Component
• Oracle Database Server (Enterprise Edition)

Discovery Timeline

• July 19, 2022 - CVE-2022-21511 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2022-21511

Vulnerability Analysis

This vulnerability resides in the Recovery component of Oracle Database Enterprise Edition. The flaw enables a privileged attacker who already possesses the EXECUTE ON DBMS_IR.EXECUTESQLSCRIPT privilege to escalate their access and achieve complete control over the Recovery component. While the attack requires network access via Oracle Net and existing high privileges, the exploitation complexity is low once these prerequisites are met.

The impact encompasses all three security pillars: confidentiality, integrity, and availability. An attacker successfully exploiting this vulnerability can read sensitive data, modify database contents, and disrupt database operations. The scope remains unchanged, meaning the impact is contained to the vulnerable component itself.

Root Cause

The vulnerability stems from improper access control within the DBMS_IR.EXECUTESQLSCRIPT procedure in the Oracle Database Recovery component. The procedure fails to adequately validate or restrict operations that can be performed by users with execute privileges, allowing them to perform actions beyond their intended authorization level. This represents a breakdown in the principle of least privilege implementation within the recovery subsystem.

Attack Vector

The attack vector is network-based, requiring the attacker to have network connectivity to the Oracle Database via Oracle Net protocol. The attacker must already possess high privileges, specifically the EXECUTE ON DBMS_IR.EXECUTESQLSCRIPT privilege. Once these conditions are met, the attacker can leverage the vulnerability through the Oracle Net protocol to escalate privileges and take over the Recovery component without requiring user interaction.

The attack flow involves:

1. Establishing a network connection to the Oracle Database via Oracle Net
2. Authenticating with credentials that have EXECUTE ON DBMS_IR.EXECUTESQLSCRIPT privilege
3. Invoking the vulnerable procedure to escalate privileges within the Recovery component
4. Achieving complete control over Oracle Database Enterprise Edition Recovery operations

Detection Methods for CVE-2022-21511

Indicators of Compromise

• Unexpected execution of the DBMS_IR.EXECUTESQLSCRIPT procedure by database users
• Anomalous activity within Oracle Database Recovery operations or logs
• Unauthorized modifications to database recovery configurations or backup data
• Unusual network connections to the Oracle Database via Oracle Net from unexpected sources

Detection Strategies

• Monitor Oracle Database audit logs for execution of DBMS_IR.EXECUTESQLSCRIPT procedures
• Implement database activity monitoring to detect privilege escalation attempts
• Configure alerting for unexpected changes to Recovery component configurations
• Review and audit users with EXECUTE ON DBMS_IR.EXECUTESQLSCRIPT privileges regularly

Monitoring Recommendations

• Enable Oracle Database Fine-Grained Auditing (FGA) for sensitive operations within the Recovery component
• Deploy SentinelOne Singularity for continuous database host monitoring and behavioral analysis
• Correlate database activity logs with network traffic analysis for Oracle Net connections
• Establish baseline behavior for users with elevated privileges to detect anomalous patterns

How to Mitigate CVE-2022-21511

Immediate Actions Required

• Apply the Oracle Critical Patch Update (CPU) from July 2022 immediately
• Review and revoke unnecessary EXECUTE ON DBMS_IR.EXECUTESQLSCRIPT privileges from database users
• Restrict network access to Oracle Database via Oracle Net to trusted sources only
• Implement network segmentation to limit exposure of database servers

Patch Information

Oracle has addressed this vulnerability in their July 2022 Critical Patch Update (CPU). Organizations should apply the patches as described in the Oracle Security Alert July 2022. Oracle notes that none of the currently supported versions are affected, suggesting the vulnerability may have been addressed in recent maintenance releases. Administrators should verify their Oracle Database version and apply appropriate updates.

Workarounds

• Revoke EXECUTE ON DBMS_IR.EXECUTESQLSCRIPT privilege from all non-essential users until patches can be applied
• Implement strict network access controls to limit Oracle Net connectivity to authorized systems
• Enable comprehensive auditing on the DBMS_IR package to monitor for exploitation attempts
• Consider temporarily disabling or restricting access to the Recovery component if not actively required

# Configuration example - Revoke unnecessary privileges
-- Review users with DBMS_IR.EXECUTESQLSCRIPT privilege
SELECT grantee, privilege, table_name 
FROM dba_tab_privs 
WHERE table_name = 'DBMS_IR';

-- Revoke privilege from non-essential users
REVOKE EXECUTE ON DBMS_IR FROM <username>;

-- Enable auditing on DBMS_IR package
AUDIT EXECUTE ON SYS.DBMS_IR BY ACCESS;