Windows RRAS Under Siege: Analyzing CVE-2025-49670's Critical Heap Overflow

A critical heap-based buffer overflow in Windows Routing and Remote Access Service (RRAS) identified as CVE-2025-49670 allows remote attackers to execute arbitrary code. Immediate patching is essential.
CVE Analysis

6 min read

ZeroPath Security Research

ZeroPath Security Research

2025-07-08

Windows RRAS Under Siege: Analyzing CVE-2025-49670's Critical Heap Overflow

Introduction

The Windows Routing and Remote Access Service (RRAS), a critical component for network routing and VPN solutions, faces a severe threat from a newly discovered heap-based buffer overflow vulnerability, CVE-2025-49670. This flaw allows remote attackers to execute arbitrary code without authentication, posing significant risks to enterprise networks and infrastructure. Given the widespread deployment of RRAS in corporate environments, immediate action is essential to prevent potential exploitation.

Technical Information

CVE-2025-49670 is a heap-based buffer overflow vulnerability within the Windows RRAS component. The vulnerability stems from inadequate bounds checking during the processing of network packets. Attackers can exploit this flaw by sending specially crafted network packets to vulnerable systems, causing memory corruption in the heap. This corruption allows attackers to overwrite adjacent memory structures, potentially gaining control over execution flow and executing arbitrary code with SYSTEM-level privileges.

The exploitation vector is entirely network-based, requiring no authentication or user interaction. This significantly simplifies the attack process, making it feasible for remote attackers to target vulnerable systems directly over the network. The RRAS service's high privilege level further exacerbates the risk, as successful exploitation could lead to complete system compromise and lateral movement within the affected network.

Patch Information

Microsoft has released a security update to address a heap-based buffer overflow vulnerability in the Windows Routing and Remote Access Service (RRAS). This vulnerability, identified as CVE-2025-49670, could allow an unauthorized attacker to execute code over a network. The patch modifies the RRAS code to properly validate input lengths and ensure that buffers are allocated with sufficient size to prevent overflow conditions. By applying this update, the RRAS service will handle network requests more securely, mitigating the risk of remote code execution.

Organizations should immediately apply this update to all affected systems to mitigate the risk of exploitation.

References

Source: This report was created using AI

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