CVE-2023-22084: Oracle MySQL Server InnoDB DoS Vulnerability

CVE-2023-22084 Overview

CVE-2023-22084 is a denial of service vulnerability affecting the InnoDB storage engine component within Oracle MySQL Server. This flaw allows a high-privileged attacker with network access to cause the MySQL Server to hang or crash repeatedly, resulting in a complete denial of service condition. The vulnerability is considered easily exploitable and can be triggered via multiple network protocols.

Critical Impact

Successful exploitation enables attackers with administrative privileges to completely disrupt database availability through repeatable crashes, potentially causing significant business disruption for applications relying on MySQL Server.

Affected Products

• Oracle MySQL Server versions 5.7.43 and prior
• Oracle MySQL Server versions 8.0.34 and prior
• Oracle MySQL Server version 8.1.0
• MariaDB (multiple affected versions)
• NetApp OnCommand Insight
• Fedora 37, 38, and 39

Discovery Timeline

• 2023-10-17 - CVE-2023-22084 published to NVD
• 2025-01-22 - Last updated in NVD database

Technical Details for CVE-2023-22084

Vulnerability Analysis

This vulnerability resides in the InnoDB storage engine, which is the default transactional storage engine for MySQL. The flaw affects the core database functionality that handles data storage and retrieval operations. When exploited, the vulnerability triggers a condition that causes the MySQL Server process to either hang indefinitely or crash, with the crash being frequently repeatable.

The attack requires high privileges (administrative access) but can be executed remotely over the network with low complexity. This means an attacker who has already compromised an administrative account, or a malicious database administrator, could leverage this vulnerability to disrupt database services. The impact is limited to availability—there is no confidentiality or integrity impact, meaning data cannot be read or modified through this vulnerability.

Root Cause

The vulnerability stems from improper handling within the InnoDB component when processing certain operations. While Oracle has not disclosed the specific technical details of the root cause, the nature of the vulnerability—causing hangs and repeatable crashes—suggests an issue with resource management, memory handling, or exception processing within the InnoDB engine. The fact that it requires high privileges indicates the vulnerable code path is only accessible through administrative functions.

Attack Vector

The attack can be carried out by an authenticated user with high privileges (such as a database administrator) who has network access to the MySQL Server. The attacker can exploit this vulnerability through multiple network protocols supported by MySQL, including the native MySQL protocol. The attack does not require any user interaction and affects only the vulnerable MySQL Server instance (unchanged scope).

An attacker would typically:

1. Authenticate to the MySQL Server with administrative credentials
2. Execute specific operations that trigger the vulnerable code path in InnoDB
3. Cause the server to crash or hang, disrupting all database operations

Since no verified proof-of-concept code is publicly available, organizations should refer to the Oracle Security Alert for detailed technical information about the vulnerability mechanism.

Detection Methods for CVE-2023-22084

Indicators of Compromise

• Unexpected MySQL Server crashes or service restarts, particularly those originating from InnoDB-related operations
• MySQL error logs showing repeated crash signatures or hang conditions in the InnoDB component
• Unusual administrative connection patterns or queries executed by privileged accounts
• Service availability interruptions coinciding with suspicious database administrative activity

Detection Strategies

• Monitor MySQL error logs for crash patterns and InnoDB-specific error messages that indicate exploitation attempts
• Implement database activity monitoring (DAM) to track privileged user operations and identify suspicious administrative queries
• Deploy SentinelOne Singularity platform to detect anomalous process behavior, including unexpected MySQL daemon crashes and restarts
• Enable MySQL audit logging to capture all administrative operations for forensic analysis

Monitoring Recommendations

• Configure alerting for MySQL Server process crashes and automatic restart events
• Establish baseline metrics for database availability and alert on deviations
• Monitor authentication logs for unusual access patterns by administrative accounts
• Implement real-time monitoring of MySQL Server health metrics including connection counts, query execution times, and InnoDB buffer pool status

How to Mitigate CVE-2023-22084

Immediate Actions Required

• Upgrade MySQL Server to versions 5.7.44 or later, 8.0.35 or later, or 8.2.0 or later as recommended by Oracle
• Review and restrict administrative privileges to only essential personnel following the principle of least privilege
• Audit all accounts with high-level database permissions and disable unnecessary administrative accounts
• Implement network segmentation to limit which systems can establish administrative connections to MySQL Server

Patch Information

Oracle has addressed this vulnerability in their October 2023 Critical Patch Update. The fix is available for all supported MySQL Server versions. Organizations should obtain patches from the official Oracle Security Alerts page. For MariaDB users, consult MariaDB security advisories for corresponding updates. Fedora users should apply updates through the standard package management system as announced in the Fedora Package Announcements. NetApp OnCommand Insight users should refer to the NetApp Security Advisory.

Workarounds

• Implement strict network access controls to limit administrative connections to trusted IP addresses only
• Enable MySQL Server's connection control plugins to prevent rapid reconnection attempts that could facilitate exploitation
• Configure MySQL to use SSL/TLS for all administrative connections, adding an additional authentication layer
• Consider placing MySQL Server behind a database firewall that can inspect and filter potentially malicious queries

# Example: Restrict administrative access to specific hosts in MySQL
# Review current user privileges
mysql -u root -p -e "SELECT user, host FROM mysql.user WHERE Super_priv='Y';"

# Update MySQL configuration to bind to specific interface
# In /etc/mysql/mysql.conf.d/mysqld.cnf
# bind-address = 127.0.0.1

# Restart MySQL service after configuration changes
sudo systemctl restart mysql