CVE-2025-49719: SQL Server 2016 Information Disclosure Flaw

CVE-2025-49719 Overview

Improper input validation in SQL Server allows an unauthorized attacker to disclose information over a network.

Critical Impact
Unauthorized information disclosure via network exploitation

Affected Products

Microsoft SQL Server 2016
Microsoft SQL Server 2017
Microsoft SQL Server 2019

Discovery Timeline

2025-07-08 - CVE CVE-2025-49719 published to NVD
2025-07-17 - Last updated in NVD database

Technical Details for CVE-2025-49719

Vulnerability Analysis

This vulnerability is classified under CWE-20: Improper Input Validation. It affects multiple versions of Microsoft SQL Server, where improper validation of input data can lead to unauthorized disclosure of sensitive information.

Root Cause

The root cause of this vulnerability lies in the server’s failure to adequately validate user inputs before processing SQL queries. This oversight allows unintended data disclosure through carefully constructed requests.

Attack Vector

The vulnerability can be exploited remotely by an unauthorized attacker via network access. The attacker sends specially crafted queries that exploit the lack of improper input validation.

sql

-- Example exploitation code (sanitized)
SELECT * FROM sensitive_data WHERE id='1 OR 1=1';

Detection Methods for CVE-2025-49719

Indicators of Compromise

Unusual or unexpected database queries
Large volume of select statements with no constraints
Abnormal outbound data flow from the SQL Server

Detection Strategies

Implement query logging and anomaly detection systems to monitor and alert on unusual database commands or access patterns. Employ application firewalls to spot and block suspected SQL injection attempts.

Monitoring Recommendations

Regularly review query logs for signs of suspicious or malicious activity. Use intrusion detection systems to notice pattern changes or repeated access failures.

How to Mitigate CVE-2025-49719

Immediate Actions Required

Audit and sanitize all incoming data on server side
Enable input validation in SQL Server configurations
Restrict network access to SQL Server

Patch Information

Microsoft provides patches for the affected SQL Server versions. Please refer to the Vendor Advisory for download and installation instructions.

Workarounds

As a workaround, implement strict input validation and sanitization practices. Utilize stored procedures to handle database queries, minimizing direct manipulation via user input.

bash

# Configuration example for input sanitization
ALTER PROCEDURE GetEmployeeData (@EmployeeID INT)
AS
BEGIN
    SET NOCOUNT ON;
    SELECT Name, Position FROM Employees WHERE EmployeeID = @EmployeeID;
END