CVE-2021-2332: Oracle LogMiner Privilege Escalation Flaw

CVE-2021-2332 Overview

CVE-2021-2332 is a vulnerability in the Oracle LogMiner component of Oracle Database Server. The flaw affects supported versions 12.1.0.2, 12.2.0.1, and 19c. An attacker with DBA privilege and network access via Oracle Net can compromise Oracle LogMiner with low attack complexity.

Successful exploitation can lead to unauthorized creation, deletion, or modification of critical data accessible through LogMiner. The attacker can also cause a complete denial of service (DoS) through a hang or repeatable crash of the component. The vulnerability impacts confidentiality, integrity, and availability.

Critical Impact

Authenticated attackers with DBA privileges can modify or destroy LogMiner-accessible data and trigger a complete denial of service against the Oracle LogMiner component over the network.

Affected Products

• Oracle Database Server 12.1.0.2
• Oracle Database Server 12.2.0.1
• Oracle Database Server 19c

Discovery Timeline

• 2021-10-19 - Oracle releases the October 2021 Critical Patch Update addressing CVE-2021-2332
• 2021-10-20 - CVE-2021-2332 published to the National Vulnerability Database (NVD)
• 2024-11-21 - Last updated in the NVD database

Technical Details for CVE-2021-2332

Vulnerability Analysis

The vulnerability resides in the Oracle LogMiner component, a utility that allows administrators to query online and archived redo log files. The flaw is exploitable over Oracle Net, the proprietary network protocol used by Oracle Database clients. The attacker must hold high privileges, specifically DBA-level access, to invoke the affected code paths.

Exploitation produces a mixed impact profile. Integrity and availability impacts are high, while confidentiality impact is limited to a subset of LogMiner-accessible data. The scope remains unchanged, meaning the impact is contained within the LogMiner security boundary.

The CWE classification is listed as NVD-CWE-noinfo, indicating Oracle did not disclose the specific weakness class. Oracle Critical Patch Updates routinely omit technical root-cause detail to limit reverse engineering opportunities.

Root Cause

Oracle did not publicly disclose the underlying defect. The combination of high integrity and availability impact with partial confidentiality impact is consistent with input handling or authorization flaws in privileged database procedures used by LogMiner. Refer to the Oracle Critical Patch Update - October 2021 advisory for the official vendor description.

Attack Vector

The attack vector is network-based through Oracle Net. The attacker must authenticate to the database and hold DBA privilege before invoking LogMiner functionality. No user interaction is required. A compromised or malicious DBA account, or any account that has been escalated to DBA through a separate flaw, can chain into this vulnerability to corrupt redo log analysis data or crash the LogMiner service.

No public proof-of-concept exploit is available, and the CVE is not listed in the CISA Known Exploited Vulnerabilities catalog.

Detection Methods for CVE-2021-2332

Indicators of Compromise

• Unexpected crashes or hangs of LogMiner sessions in Oracle alert logs
• Anomalous invocations of DBMS_LOGMNR procedures from sessions that do not normally perform redo log analysis
• Unexplained modifications to LogMiner dictionary or data accessed through V$LOGMNR_CONTENTS

Detection Strategies

• Audit all DBA-privileged sessions that call LogMiner packages, correlating session origin IP with approved administrative hosts
• Enable Oracle Unified Auditing for the DBMS_LOGMNR and DBMS_LOGMNR_D packages to capture every invocation
• Compare Oracle Database patch inventory against the October 2021 Critical Patch Update baseline using opatch lsinventory

Monitoring Recommendations

• Forward Oracle alert logs and audit trails to a centralized SIEM for anomaly detection on LogMiner usage patterns
• Alert on repeated LogMiner crashes or instance-level errors involving the redo log mining subsystem
• Monitor privileged account activity, especially new or rarely used DBA accounts authenticating over Oracle Net

How to Mitigate CVE-2021-2332

Immediate Actions Required

• Apply the Oracle October 2021 Critical Patch Update to all affected Database Server installations
• Inventory all instances of Oracle Database 12.1.0.2, 12.2.0.1, and 19c to confirm patch coverage
• Review and reduce the population of accounts holding the DBA role to the minimum required

Patch Information

Oracle released the fix in the October 2021 Critical Patch Update. Administrators should download and apply the appropriate patch bundle for their database version from the Oracle Critical Patch Update Advisory - October 2021. After patching, validate using opatch lsinventory and restart the database instance.

Workarounds

• Restrict network access to the Oracle listener using Oracle Net valid node checking or firewall rules so only trusted administrative hosts can reach the database
• Revoke LogMiner package execution privileges from any role that does not strictly require redo log analysis
• Enforce strong authentication and session monitoring on all DBA accounts pending patch deployment

# Verify patch installation after applying the October 2021 CPU
$ORACLE_HOME/OPatch/opatch lsinventory | grep -i "33192793\|cpuoct2021"

# Restrict LogMiner package execution to a dedicated role
REVOKE EXECUTE ON SYS.DBMS_LOGMNR FROM PUBLIC;
REVOKE EXECUTE ON SYS.DBMS_LOGMNR_D FROM PUBLIC;