CVE-2024-27766
📋 TL;DR
This CVE describes a potential remote code execution vulnerability in MariaDB v.11.1 through the lib_mysqludf_sys.so function. The vulnerability allows attackers to execute arbitrary code on affected systems, though the MariaDB Foundation disputes this claim, stating no privilege boundary is crossed. Systems running vulnerable MariaDB versions with the UDF function enabled are potentially affected.
💻 Affected Systems
- MariaDB
📦 What is this software?
Mariadb by Mariadb
⚠️ Risk & Real-World Impact
Worst Case
Remote attacker gains full system control through arbitrary code execution, potentially leading to data theft, system compromise, or lateral movement.
Likely Case
Limited impact due to the disputed nature and requirement for specific configurations; most likely unauthorized data access or denial of service.
If Mitigated
Minimal impact if proper access controls, network segmentation, and least privilege principles are implemented.
🎯 Exploit Status
Exploitation requires database access and specific UDF configuration; the vulnerability is disputed by the vendor.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not applicable - vulnerability disputed by vendor
Vendor Advisory: No official advisory - vulnerability disputed
Restart Required: No
Instructions:
No official patch; consider upgrading to latest MariaDB version and removing unnecessary UDF functions.
🔧 Temporary Workarounds
Remove lib_mysqludf_sys.so UDF
allUninstall or disable the vulnerable UDF function to prevent exploitation
DROP FUNCTION IF EXISTS sys_exec;
DROP FUNCTION IF EXISTS sys_eval;
Restrict UDF Loading
allConfigure MariaDB to prevent loading of external UDF functions
Set 'allow-suspicious-udfs = FALSE' in my.cnf
🧯 If You Can't Patch
- Implement strict network access controls to limit database exposure
- Apply principle of least privilege to database users and remove unnecessary permissions
🔍 How to Verify
Check if Vulnerable:
Check if lib_mysqludf_sys.so is installed: SELECT * FROM mysql.func WHERE name LIKE 'sys_%';Check Version:
SELECT VERSION();Verify Fix Applied:
Verify UDF functions are removed: SELECT * FROM mysql.func WHERE name LIKE 'sys_%'; should return empty📡 Detection & Monitoring
Log Indicators:
- Unusual UDF function creation or execution
- Suspicious database queries attempting to load external functions
Network Indicators:
- Unexpected database connections from unauthorized sources
- Anomalous traffic patterns to database port
SIEM Query:
source="mariadb.log" AND ("CREATE FUNCTION" OR "lib_mysqludf_sys" OR "sys_exec" OR "sys_eval")