CVE-2026-83788 in Windows
Summary
by MITRE • 10/14/2026
Buffer over-read in Windows RNDIS allows an unauthorized attacker to disclose information with a physical attack.
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Analysis
by VulDB Data Team • 10/14/2026
The vulnerability identified as CVE-2023-47965 represents a critical security flaw within the Remote Network Driver Interface Specification (RNDIS) implementation found in Microsoft Windows operating systems. RNDIS is a protocol that allows devices, such as smartphones or external network adapters, to communicate with a host computer over USB by emulating an Ethernet connection. This specific vulnerability stems from a buffer over-read condition located deep within the driver's packet processing logic. When the system processes incoming data packets via this interface, it fails to adequately validate the length of the payload against the allocated memory buffers before reading them. Consequently, if a malicious actor provides crafted input that exceeds the expected bounds but remains within certain limits, the driver will read beyond the intended buffer boundaries into adjacent memory regions. This behavior is classified under CWE-126, which denotes Buffer Over-read, indicating that the application reads data past the end of a buffer rather than writing to it, leading to potential information leakage or system instability depending on what sensitive data resides in those adjacent memory locations.
The operational impact of this vulnerability is significant due to its reliance on physical proximity for exploitation. An attacker with direct access to the target machine's USB ports can connect a malicious device designed to exploit this flaw. By sending specifically crafted RNDIS packets, the attacker triggers the out-of-bounds read operation within the kernel-mode driver. The primary consequence of this action is the disclosure of sensitive information from the host system’s memory space. This could include cryptographic keys, authentication tokens, user credentials, or other proprietary data stored in adjacent memory blocks that were not intended to be exposed. While the vulnerability does not inherently allow for arbitrary code execution or privilege escalation on its own, the ability to leak kernel-mode memory contents provides an attacker with valuable intelligence that can facilitate further attacks, such as bypassing security controls like Kernel Patch Protection (PatchGuard) or extracting session keys used in encrypted communications. This aligns with ATT&CK technique T1057, Process Discovery, and more broadly T1005, Data from Local System, highlighting the risk of unauthorized data exfiltration through local physical access vectors.
Mitigating this vulnerability requires a multi-layered approach focusing on both technical controls and procedural safeguards. The most effective mitigation is to apply the security update provided by Microsoft that patches the buffer validation logic within the RNDIS driver. Organizations should prioritize deploying these updates across all endpoints, particularly those used in high-security environments or public-facing locations where physical access cannot be strictly controlled. In addition to patching, administrators can reduce the attack surface by disabling unnecessary USB ports or restricting their use through Group Policy settings that prevent unauthorized devices from establishing network connections via RNDIS. Implementing strict device control policies ensures that only approved hardware can interact with the system’s networking stack. Furthermore, physical security measures such as port locks and surveillance in sensitive areas serve as essential deterrents against attackers attempting to exploit this vulnerability through direct physical access. Regular audits of USB usage policies and continuous monitoring for anomalous network traffic patterns originating from local interfaces can also aid in early detection of potential exploitation attempts.