CVE-2025-49759
📋 TL;DR
This SQL injection vulnerability in Microsoft SQL Server allows authenticated attackers to execute arbitrary SQL commands, potentially leading to privilege escalation. It affects SQL Server instances accessible over a network where attackers have valid credentials. Organizations using vulnerable SQL Server versions are at risk.
💻 Affected Systems
- Microsoft SQL Server
📦 What is this software?
Sql Server 2016 by Microsoft
Sql Server 2016 by Microsoft
Sql Server 2017 by Microsoft
Sql Server 2017 by Microsoft
Sql Server 2019 by Microsoft
Sql Server 2019 by Microsoft
Sql Server 2022 by Microsoft
Sql Server 2022 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise, data exfiltration, lateral movement to other systems, and persistent backdoor installation.
Likely Case
Unauthorized data access, privilege escalation within the database, and potential data manipulation.
If Mitigated
Limited impact due to network segmentation, least privilege access, and input validation controls.
🎯 Exploit Status
Requires authenticated access. SQL injection exploitation typically requires understanding of database schema.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific patch versions
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-49759
Restart Required: Yes
Instructions:
1. Review Microsoft Security Update Guide for affected versions. 2. Apply latest cumulative update for your SQL Server version. 3. Restart SQL Server services. 4. Test application functionality.
🔧 Temporary Workarounds
Implement Input Validation
allAdd parameterized queries and input validation in all applications connecting to SQL Server
Restrict Network Access
windowsLimit SQL Server access to specific IP addresses using firewall rules
New-NetFirewallRule -DisplayName "SQL Server Restrict" -Direction Inbound -LocalPort 1433 -Protocol TCP -RemoteAddress 192.168.1.0/24 -Action Allow
🧯 If You Can't Patch
- Implement strict network segmentation and firewall rules to limit SQL Server access
- Apply principle of least privilege to all database accounts and remove unnecessary permissions
🔍 How to Verify
Check if Vulnerable:
Check SQL Server version against Microsoft Security Update Guide. Run: SELECT @@VERSIONCheck Version:
SELECT @@VERSIONVerify Fix Applied:
Verify patch installation via Windows Update history or SQL Server build number. Run: SELECT SERVERPROPERTY('ProductVersion')📡 Detection & Monitoring
Log Indicators:
- Unusual SQL query patterns
- Multiple failed login attempts followed by successful login
- Privilege escalation attempts in SQL logs
Network Indicators:
- Unusual SQL query traffic patterns
- SQL commands from unexpected sources
SIEM Query:
source="sql_server" AND (query="xp_cmdshell" OR query="sp_addsrvrolemember" OR query="GRANT" OR query="ALTER")