CVE-2024-21233: Oracle Database Server Auth Bypass Flaw

CVE-2024-21233 Overview

CVE-2024-21233 affects the Oracle Database Core component of Oracle Database Server. Oracle disclosed the issue in the October 2024 Critical Patch Update. A low-privileged attacker holding the CREATE SESSION privilege can exploit the flaw over Oracle Net. Successful exploitation allows unauthorized update, insert, or delete access to a subset of Oracle Database Core data. The vulnerability impacts integrity only, with no direct confidentiality or availability consequences. Affected releases include Oracle Database 19.3 through 19.24, 21.3 through 21.15, and 23.4 through 23.5. The flaw is categorized under [CWE-203] (Observable Discrepancy) in NVD records.

Critical Impact
Authenticated remote attackers can perform unauthorized write operations against Oracle Database Core data, undermining data integrity in affected database instances.

Affected Products

Oracle Database Server 19.3 through 19.24
Oracle Database Server 21.3 through 21.15
Oracle Database Server 23.4 through 23.5

Discovery Timeline

2024-10-15 - CVE CVE-2024-21233 published to NVD as part of Oracle Critical Patch Update October 2024
2024-10-31 - Last updated in NVD database

Technical Details for CVE-2024-21233

Vulnerability Analysis

The vulnerability resides in the Oracle Database Core component, which manages fundamental database operations including SQL execution and data access. An attacker with a valid database session can reach the vulnerable code path through standard Oracle Net connections. The attack complexity is low, and no user interaction is required. The impact is limited to integrity, allowing partial modification of Oracle Database Core accessible data without disclosing data or causing service disruption. The classification under [CWE-203] suggests the flaw involves an observable behavioral difference that leaks state used to perform unauthorized writes. Exploitation requires only the CREATE SESSION privilege, which is commonly granted to application and reporting accounts.

Root Cause

The root cause sits within Oracle Database Core processing logic accessible to authenticated sessions. Oracle has not published low-level technical details. The NVD assignment of [CWE-203] indicates an observable discrepancy condition that an attacker can leverage to influence write operations on protected data structures.

Attack Vector

The attack vector is network-based through Oracle Net. The attacker authenticates with low privileges, then issues crafted requests against the Oracle Database Core component. No elevated role, administrative privilege, or interactive user action is required to trigger the vulnerable code path.

No public proof-of-concept code is available. Refer to the Oracle Security Alert - October 2024 for vendor guidance.

Detection Methods for CVE-2024-21233

Indicators of Compromise

Unexpected UPDATE, INSERT, or DELETE operations originating from low-privileged accounts that should hold read-only or limited access
Anomalous SQL activity from accounts holding only CREATE SESSION against Oracle Database Core objects
Oracle Net connections from unexpected client hosts or service accounts performing write operations

Detection Strategies

Enable Oracle Unified Auditing for DML statements on sensitive schemas and monitor for write activity from non-privileged sessions
Correlate audit trail entries with application baselines to surface unauthorized modifications
Track use of the CREATE SESSION privilege across the user inventory and flag accounts performing unusual data modification

Monitoring Recommendations

Forward Oracle audit logs to a centralized analytics platform for baseline deviation analysis
Monitor DBA_AUDIT_TRAIL and UNIFIED_AUDIT_TRAIL for write actions against core data dictionary and application tables
Alert on Oracle Net listener connections from previously unseen client IP ranges or service identifiers

How to Mitigate CVE-2024-21233

Immediate Actions Required

Apply the October 2024 Critical Patch Update for all affected Oracle Database Server versions
Inventory accounts that hold the CREATE SESSION privilege and revoke it where not required
Review and tighten DML privileges on sensitive schemas accessible to general database users

Patch Information

Oracle released fixes for CVE-2024-21233 in the October 2024 Critical Patch Update. Patches are available for Oracle Database 19c, 21c, and 23ai release lines. Refer to the Oracle Security Alert - October 2024 for patch download instructions and version-specific guidance.

Workarounds

Restrict Oracle Net access to the database listener using tcp.validnode_checking and tcp.invited_nodes in sqlnet.ora
Enforce least privilege on database accounts and remove unnecessary write permissions on core objects
Enable Unified Auditing policies that capture DML on sensitive tables until patching completes

bash

# Example sqlnet.ora hardening to limit listener exposure
tcp.validnode_checking = yes
tcp.invited_nodes = (10.0.0.10, 10.0.0.11, app-server-01)
tcp.excluded_nodes = (0.0.0.0/0)