CVE-2023-29356
📋 TL;DR
CVE-2023-29356 is a use-after-free vulnerability in Microsoft ODBC Driver for SQL Server that allows remote code execution. Attackers can exploit this by sending specially crafted queries to vulnerable systems. This affects applications using affected ODBC driver versions to connect to SQL Server.
💻 Affected Systems
- Microsoft ODBC Driver for SQL Server
📦 What is this software?
Sql Server by Microsoft
Sql Server by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining SYSTEM/administrator privileges, enabling data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Application compromise leading to data exfiltration, lateral movement within the network, or service disruption.
If Mitigated
Limited impact due to network segmentation, least privilege configurations, and proper input validation preventing exploitation.
🎯 Exploit Status
Exploitation requires the ability to send SQL queries through an application using the vulnerable driver. No public exploit code is available as of knowledge cutoff.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: ODBC Driver 17.11.1.1 and 18.3.2.1
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-29356
Restart Required: Yes
Instructions:
1. Identify applications using Microsoft ODBC Driver for SQL Server. 2. Download updated drivers from Microsoft Download Center. 3. Install updated drivers on all affected systems. 4. Restart applications/services using the ODBC driver. 5. Test application functionality after update.
🔧 Temporary Workarounds
Network Segmentation
allRestrict network access to SQL Server instances to only trusted applications and users.
Application Input Validation
allImplement strict input validation in applications to prevent malicious SQL queries.
🧯 If You Can't Patch
- Implement network segmentation to isolate SQL Server connections
- Apply principle of least privilege to database accounts and application service accounts
🔍 How to Verify
Check if Vulnerable:
Check ODBC driver version in applications: On Windows use ODBC Data Source Administrator or check installed programs. On Linux check package manager or driver files.Check Version:
Windows: odbcconf /LODBC | findstr Driver. Linux: odbcinst -q -d | grep -i sqlVerify Fix Applied:
Verify ODBC driver version is 17.11.1.1 or higher for 17.x, or 18.3.2.1 or higher for 18.x.📡 Detection & Monitoring
Log Indicators:
- Unusual SQL query patterns
- ODBC driver error messages in application logs
- Failed connection attempts with malformed queries
Network Indicators:
- Unusual SQL traffic patterns
- Connection attempts from unexpected sources to SQL Server ports
SIEM Query:
source="application_logs" AND ("ODBC" OR "SQLDriverConnect") AND (error OR exception OR fail*)