CVE-2025-49688: Double Free Vulnerability in Windows RRAS Opens Door for Unauthorized Code Execution

Overview

The cybersecurity landscape is riddled with vulnerabilities, and the newest one to join the fray is CVE-2025-49688, a critical flaw in the Windows Routing and Remote Access Service (RRAS). This vulnerability, if exploited, allows a malicious actor to execute unauthorized code over a network, compromising the system and potentially leading to data leakage. It is a grave concern for all Windows users, especially corporations and organizations using RRAS, as it places their sensitive data and system integrity at risk.

Vulnerability Summary

CVE ID: CVE-2025-49688
Severity: High, 8.8 (CVSS score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Unauthorized code execution, potential system compromise, and data leakage

Affected Products

Product | Affected Versions

Microsoft Windows Server | 2022, 2019, 2016, 2012 R2, 2012

How the Exploit Works

The exploit takes advantage of a double-free flaw in Windows RRAS. A double-free error occurs when the application tries to free a memory block that has already been freed, leading to unexpected behavior including crashes, data corruption, and-in this case-arbitrary code execution.
An attacker can send specially crafted packets to the vulnerable system over the network. The system, upon processing these packets, triggers the double-free error, which in turn allows the attacker to execute arbitrary code in the context of the system user, leading to a full compromise of the system.

Conceptual Example Code

Here’s a conceptual example of how an attacker might exploit this vulnerability. This is a simplified representation and the actual exploit would be more complex and specific:

# Create a malicious payload
echo -e '\x90\x90\x90\x90...' > payload.bin
# Send the payload to the vulnerable server
nc target.example.com 3389 < payload.bin

In this conceptual example, `nc` is netcat, a utility for sending data across networks. `target.example.com` is the target server, `3389` is the port associated with Windows RRAS, and `payload.bin` is a binary file containing the malicious payload. The payload here is represented by the series of `\x90`, which is a NOP (No Operation) instruction in x86 assembly. In a real-world scenario, the payload would comprise actual malicious code.
Please note that this code is provided for educational and demonstration purposes only and should not be used maliciously.