CVE-2025-49717: Microsoft SQL Server 2019 RCE Vulnerability

CVE-2025-49717 Overview

Heap-based buffer overflow in SQL Server allows an authorized attacker to execute code over a network.

Critical Impact

This vulnerability allows for code execution with high impact on confidentiality, integrity, and availability.

Affected Products

• Microsoft SQL Server 2019
• Microsoft SQL Server 2022

Discovery Timeline

• Not Available - Vulnerability discovered by Not Available
• Not Available - Responsible disclosure to Microsoft
• Not Available - CVE CVE-2025-49717 assigned
• Not Available - Microsoft releases security patch
• 2025-07-08 - CVE CVE-2025-49717 published to NVD
• 2025-07-17 - Last updated in NVD database

Technical Details for CVE-2025-49717

Vulnerability Analysis

The vulnerability is a heap-based buffer overflow in Microsoft SQL Server, which could be exploited by an authenticated attacker to run arbitrary code on the server. This vulnerability uses a network attack vector and presents high severity due to the potential for full system compromise.

Root Cause

Improper bounds checking on user-supplied input to a network-exposed service in SQL Server.

Attack Vector

The attack is executed over the network by exploiting the vulnerable component in the SQL Server, requiring network access and a valid user account.

// Example exploitation code (sanitized)
#include <stdio.h>
#include <string.h>

int vulnerable_function(char *input) {
    char buffer[64];
    strcpy(buffer, input);
    return 0;
}

int main(int argc, char **argv) {
    if (argc != 2) {
        printf("Usage: %s <input>\n", argv[0]);
        return 1;
    }
    return vulnerable_function(argv[1]);
}

Detection Methods for CVE-2025-49717

Indicators of Compromise

• Unusual network traffic to and from SQL Server hosts
• Processes running with escalated privileges
• Execution of unexpected SQL queries

Detection Strategies

Monitoring network traffic for anomalies, especially connections that attempt to exploit heap-based overflows in SQL Server. Leveraging endpoint protection solutions like SentinelOne to detect unauthorized code execution attempts can be crucial.

Monitoring Recommendations

Implement continuous monitoring of network activities and SQL server logs to detect anomalous behavior indicative of exploitation attempts.

How to Mitigate CVE-2025-49717

Immediate Actions Required

• Apply the latest security patch released by Microsoft
• Restrict network access to systems running SQL Server
• Enforce strict access controls and regularly audit user permissions

Patch Information

Patches are available through the Microsoft Security Update Guide at Microsoft's advisory.

Workarounds

• Limit access to SQL Server to only trusted networks and authenticated users.

# Configuration example
iptables -A INPUT -p tcp -s trusted_network --dport 1433 -j ACCEPT
iptables -A INPUT -p tcp --dport 1433 -j DROP