CVE-2025-49657 in Windows
Summary
by MITRE • 07/08/2025
Heap-based buffer overflow in Windows Routing and Remote Access Service (RRAS) allows an unauthorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 07/09/2025
This vulnerability represents a critical heap-based buffer overflow flaw within the Windows Routing and Remote Access Service that enables remote code execution by unauthorized attackers. The vulnerability exists in the RRAS component responsible for handling network routing and remote access functionalities, making it a prime target for exploitation in enterprise environments where routing services are commonly deployed. The heap overflow occurs when the service processes maliciously crafted network packets or configuration data, leading to memory corruption that can be leveraged to execute arbitrary code with elevated privileges.
The technical implementation of this vulnerability stems from inadequate input validation within the RRAS service routines that handle various network protocols and remote access authentication mechanisms. When processing malformed data structures or oversized buffers in network communication channels, the service fails to properly bounds-check heap-allocated memory regions, creating opportunities for attackers to overwrite adjacent memory locations. This type of vulnerability falls under the CWE-121 heap-based buffer overflow category, which is classified as a critical security weakness in software systems. The flaw typically manifests when RRAS processes specific types of network traffic such as routing updates, remote access protocol communications, or authentication requests that contain oversized or malformed data fields.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass full system compromise and potential lateral movement within networks. Attackers can exploit this weakness from remote locations without requiring local access credentials, making it particularly dangerous for organizations with exposed routing services or remote access infrastructure. The vulnerability affects Windows systems running RRAS functionality including Windows Server 2008, 2012, and related versions where the service is enabled and configured to handle network traffic. Successful exploitation can result in complete system takeover, data exfiltration, and establishment of persistent backdoors within the network infrastructure. This aligns with ATT&CK technique T1059.007 for remote code execution through network services and represents a significant threat vector for advanced persistent threats targeting enterprise networking infrastructure.
Mitigation strategies should prioritize immediate patch deployment from Microsoft Security Updates to address the specific heap overflow vulnerability in RRAS components. Organizations must also implement network segmentation to isolate critical routing services from general network traffic, disable unnecessary RRAS functionality on systems where it is not required, and monitor network protocols for anomalous traffic patterns that might indicate exploitation attempts. The implementation of network access control lists and firewall rules to restrict communication with RRAS services can significantly reduce the attack surface. Additionally, regular security assessments should verify that RRAS configurations do not expose unnecessary services or protocols, while endpoint detection and response solutions should be configured to monitor for suspicious heap memory operations and process injection techniques that may indicate exploitation attempts.