Description

Heap-based buffer overflow in Windows RNDIS allows an unauthorized attacker to execute code over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-09-08T18:19:47.970Z",
  "pubdate": "2026-09-08T18:19:47.970Z",
  "executiveSummary": "A critical heap-based buffer overflow vulnerability exists within the Windows Remote Network Driver Interface Specification (RNDIS) implementation.\nThis vulnerability resides in the processing of RNDIS network packets, potentially allowing a remote, unauthenticated attacker to achieve arbitrary code execution on the target system.\nThe flaw stems from improper boundary checking when handling RNDIS messages, which leads to heap memory corruption.\nSuccessful exploitation allows an attacker to execute malicious payloads with the privileges of the system kernel or the RNDIS driver context.\nGiven that RNDIS is frequently used for USB-based networking, exploitation typically requires an attacker to have physical access to the USB port or the ability to inject malicious RNDIS frames if the network stack is exposed over a physical interface.\nThe risk is severe as it enables full system compromise, data exfiltration, and persistent access, bypassing traditional user-mode security boundaries.\nNo user interaction is required for a successful exploit if the device is connected to an attacker-controlled interface.",
  "technicalDetails": "The vulnerability is localized to the RNDIS driver component in Windows responsible for parsing and handling RNDIS protocol messages. RNDIS defines a set of messages for initializing, configuring, and managing remote network devices over various transports, primarily USB.\nThe root cause of the heap-based buffer overflow is an insufficient validation of length fields provided within the RNDIS message headers. When the driver processes these messages, it allocates heap memory to store the incoming data payload. If the provided length field exceeds the allocated buffer size, a heap-based memory corruption occurs during the memory copy operation.\nExploitation involves an attacker crafting a malicious RNDIS packet containing an oversized payload designed to overflow the heap buffer. By carefully controlling the contents of the overflow, an attacker can overwrite adjacent heap metadata or function pointers. This memory manipulation allows for the redirection of the execution flow to an attacker-controlled address or a Return-Oriented Programming (ROP) chain.\nThe attack flow follows a structured sequence: 1) The attacker connects a malicious RNDIS device or communicates via an exposed RNDIS interface; 2) The attacker sends a malformed RNDIS command packet to the Windows host; 3) The target system's RNDIS driver parses the message and triggers the vulnerable memory copy function; 4) The overflow corrupts the heap, allowing the attacker to overwrite critical objects; 5) The attacker triggers the execution of injected shellcode or ROP gadgets.\nBecause the RNDIS driver operates within a high-privilege context (typically Kernel mode or System context), the impact of successful exploitation is significant. An attacker can bypass modern exploit mitigations such as Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) by leveraging heap grooming techniques or memory layout disclosure vulnerabilities to identify target addresses. The post-exploitation result is arbitrary code execution, granting the attacker full control over the host operating system, enabling the deployment of persistence mechanisms, rootkits, or lateral movement within the network."
}