CVE-2024-21159
📋 TL;DR
This vulnerability in MySQL Server's InnoDB component allows high-privileged attackers with network access to cause a denial of service by crashing or hanging the server. It affects MySQL Server versions 8.0.36 and prior, and 8.3.0 and prior. Attackers need administrative database privileges to exploit this vulnerability.
💻 Affected Systems
- Oracle MySQL Server
📦 What is this software?
Mysql by Oracle
Mysql by Oracle
⚠️ Risk & Real-World Impact
Worst Case
Complete unavailability of MySQL Server leading to application downtime and service disruption
Likely Case
Targeted DoS attacks against critical database servers by malicious insiders or compromised admin accounts
If Mitigated
Limited impact due to proper access controls and network segmentation
🎯 Exploit Status
Exploitation requires high-privileged database account (PR:H) but is described as 'easily exploitable'
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: MySQL 8.0.37 and 8.3.1 or later
Vendor Advisory: https://www.oracle.com/security-alerts/cpujul2024.html
Restart Required: Yes
Instructions:
1. Download latest MySQL version from Oracle website. 2. Backup databases. 3. Stop MySQL service. 4. Install updated version. 5. Start MySQL service. 6. Verify version and functionality.
🔧 Temporary Workarounds
Restrict administrative access
allLimit high-privileged database accounts to trusted users and systems only
REVOKE SUPER, PROCESS, SHUTDOWN ON *.* FROM 'user'@'%';
DROP USER 'unnecessary_admin'@'%';
Network segmentation
linuxRestrict network access to MySQL ports (3306 default) to only required application servers
iptables -A INPUT -p tcp --dport 3306 -s trusted_ip -j ACCEPT
iptables -A INPUT -p tcp --dport 3306 -j DROP
🧯 If You Can't Patch
- Implement strict access controls: Only grant administrative privileges to absolutely necessary users
- Monitor for unusual administrative activity and failed connection attempts from unexpected sources
🔍 How to Verify
Check if Vulnerable:
Run 'SELECT VERSION();' in MySQL and check if version is 8.0.36 or earlier, or 8.3.0 or earlierCheck Version:
mysql --version OR SELECT VERSION();Verify Fix Applied:
After patching, verify version is 8.0.37+ or 8.3.1+ and test database functionality📡 Detection & Monitoring
Log Indicators:
- Unexpected server crashes or restarts
- Multiple failed connection attempts from admin accounts
- InnoDB error messages in MySQL error log
Network Indicators:
- Unusual traffic patterns to MySQL port from unexpected sources
- Multiple rapid connections from single admin account
SIEM Query:
source="mysql_error.log" AND ("crash" OR "hang" OR "InnoDB error")