CVE-2025-50082
📋 TL;DR
This vulnerability in MySQL Server's optimizer component allows authenticated attackers with low privileges to cause denial of service by crashing or hanging the database server. It affects MySQL versions 8.0.0-8.0.42, 8.4.0-8.4.5, and 9.0.0-9.3.0. Attackers need network access and valid credentials to exploit this vulnerability.
💻 Affected Systems
- Oracle MySQL Server
📦 What is this software?
Mysql by Oracle
Mysql by Oracle
Mysql by Oracle
⚠️ Risk & Real-World Impact
Worst Case
Complete database unavailability leading to application downtime, data loss from interrupted transactions, and potential cascading failures in dependent systems.
Likely Case
Service disruption causing application errors, failed queries, and degraded performance until database restart.
If Mitigated
Limited impact with proper network segmentation and privilege restrictions, though service disruption still possible.
🎯 Exploit Status
Oracle describes it as 'easily exploitable' but requires authenticated access. No public exploit details available yet.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after 8.0.42, 8.4.5, and 9.3.0
Vendor Advisory: https://www.oracle.com/security-alerts/cpujul2025.html
Restart Required: Yes
Instructions:
1. Download latest MySQL version from Oracle website. 2. Backup databases and configuration. 3. Stop MySQL service. 4. Install updated version. 5. Restart MySQL service. 6. Verify functionality.
🔧 Temporary Workarounds
Network Access Restriction
allLimit MySQL network access to only trusted application servers and administrative systems.
# Configure MySQL bind-address to specific IP
bind-address = 192.168.1.100
# Use firewall rules
iptables -A INPUT -p tcp --dport 3306 -s trusted_ip -j ACCEPT
iptables -A INPUT -p tcp --dport 3306 -j DROP
Privilege Minimization
allReduce attack surface by granting minimal necessary privileges to application accounts.
# Revoke unnecessary privileges
REVOKE ALL PRIVILEGES ON *.* FROM 'app_user'@'%';
GRANT SELECT, INSERT, UPDATE, DELETE ON app_db.* TO 'app_user'@'%';
🧯 If You Can't Patch
- Implement strict network segmentation and firewall rules to limit MySQL access to essential systems only.
- Enforce principle of least privilege for all database users and regularly audit account permissions.
🔍 How to Verify
Check if Vulnerable:
Check MySQL version with 'SELECT VERSION();' and compare against affected ranges.Check Version:
mysql -u root -p -e 'SELECT VERSION();'Verify Fix Applied:
Verify version is above affected ranges and test database functionality under normal load.📡 Detection & Monitoring
Log Indicators:
- Unexpected MySQL crashes or restarts
- Error logs showing optimizer-related failures
- Abnormal termination messages in error log
Network Indicators:
- Multiple failed authentication attempts followed by service disruption
- Unusual query patterns from low-privilege accounts
SIEM Query:
source="mysql_error.log" ("crash" OR "segmentation fault" OR "abnormal shutdown") AND ("optimizer" OR "CVE-2025-50082")