Windows RRAS Under Siege: Analyzing CVE-2025-47998 Heap-Based Buffer Overflow

Introduction

Windows Routing and Remote Access Service (RRAS) is a crucial component for VPN and remote connectivity in enterprise environments. However, a newly discovered heap-based buffer overflow vulnerability, CVE-2025-47998, places these systems at severe risk. This flaw enables unauthenticated attackers to execute arbitrary code remotely, potentially leading to full system compromise.

Technical Information

CVE-2025-47998 is a heap-based buffer overflow vulnerability in Windows RRAS. The root cause lies in improper handling of memory operations when processing specially crafted network packets. An attacker can exploit this vulnerability remotely by sending oversized packets to RRAS endpoints, such as TCP/UDP ports 1701 (L2TP) or 1723 (PPTP). This triggers memory corruption, overwriting adjacent memory regions and allowing attackers to execute arbitrary code with SYSTEM-level privileges.

The vulnerability affects all Windows versions running RRAS prior to the July 2025 security update.

Attack Vector

Attackers exploit this vulnerability by sending malicious packets directly to RRAS services exposed to the network. No user interaction or authentication is required, making this vulnerability particularly dangerous for internet-facing RRAS deployments.

Patch Information

Microsoft has addressed the heap-based buffer overflow vulnerability in the Windows Routing and Remote Access Service (RRAS) by releasing a security update as part of their July 2025 Patch Tuesday. This update modifies how RRAS handles memory operations to prevent unauthorized code execution over a network. Administrators are strongly advised to apply this update promptly to mitigate potential risks associated with this vulnerability.

Patch source: Microsoft Security Response Center

Affected Systems and Versions

Windows Server 2012 R2 through Windows Server 2022
Windows 10 and Windows 11 endpoints with RRAS enabled

All versions prior to the July 2025 security update are vulnerable.

Vendor Security History

Microsoft has previously encountered vulnerabilities in RRAS, including CVE-2025-33064 and legacy issues such as MS06-025. Historically, Microsoft's response to RRAS vulnerabilities has improved, with timely patches now standard practice during their monthly Patch Tuesday updates.

References

Source: This report was created using AI

If you have suggestions for improvement or feedback, please reach out to us at [email protected]

A critical heap-based buffer overflow in Windows RRAS (CVE-2025-47998) enables unauthenticated remote attackers to execute arbitrary code. Immediate patching is essential.

CVE Analysis