CVE-2026-69571 in Windows
Summary
by MITRE • 09/09/2026
Heap-based buffer overflow in Windows USB Audio Class driver (usbaudio.sys) allows an authorized attacker to elevate privileges locally.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified involves a heap-based buffer overflow within the Microsoft Windows USB Audio Class driver, specifically usbaudio.sys. This component is responsible for managing audio devices that adhere to the Universal Serial Bus Audio Device Class specification, facilitating communication between the operating system and connected hardware such as microphones, speakers, and headsets. The flaw resides in how the driver processes input data from these peripheral devices without adequately validating buffer boundaries or length parameters before copying data into allocated memory regions on the heap. This lack of rigorous bounds checking creates a scenario where an attacker can supply crafted USB audio descriptors or control requests that exceed the expected size limits, causing the driver to write beyond the allocated buffer space.
From a technical perspective, this overflow allows for arbitrary code execution within the kernel mode context because usbaudio.sys operates at Ring 0 with high privileges. When the heap corruption occurs, it can overwrite adjacent memory structures such as function pointers or object headers, which are subsequently dereferenced by the driver logic. By carefully crafting the malicious input payload, an attacker can control the instruction pointer and redirect execution flow to shellcode injected into the process space. This mechanism effectively bypasses standard user-mode security boundaries, granting the attacker full administrative privileges on the affected system without requiring prior elevation or authentication beyond physical access to a USB port or network-accessible audio device emulation.
The operational impact of this vulnerability is severe due to its potential for local privilege escalation. An authorized attacker who has logged into the target machine can exploit this flaw to gain SYSTEM-level access, which represents the highest level of trust in Windows security architecture. With such elevated privileges, the attacker can install rootkits, modify system configurations, create new administrative accounts, or exfiltrate sensitive data with impunity. Furthermore, because the vulnerability exists within a core driver component that is often loaded early during boot processes and remains resident for the duration of the session, it provides persistent access if not properly remediated. The attack vector typically requires physical interaction to connect a malicious USB device or potentially remote exploitation through specialized audio streaming protocols depending on the specific implementation details and network exposure of related services.
Mitigation strategies primarily involve applying the latest security updates provided by Microsoft that patch this heap overflow condition within usbaudio.sys. Organizations should ensure that all endpoints are kept current with cumulative patches to close known gaps in driver validation logic. In environments where physical security is a concern, implementing strict USB port policies through Group Policy or endpoint detection and response solutions can restrict the use of unauthorized audio peripherals. Additionally, enabling hardware-enforced stack protection features such as Kernel Address Space Layout Randomization (KASLR) and Data Execution Prevention (DEP) can mitigate exploitation attempts by making it more difficult for attackers to reliably predict memory addresses required for successful code execution.
This vulnerability aligns with Common Weakness Enumeration identifier CWE-120, which describes buffer copy without checking size limits, a classic category of memory safety errors prevalent in C and C++ based drivers. In the context of the MITRE ATT&CK framework, this flaw facilitates techniques associated with Privilege Escalation via Exploitation for Local Elevation (T1068) and potentially Defense Evasion through Kernel Mode exploits if rootkit capabilities are leveraged post-exploitation. Understanding these mappings helps security teams prioritize remediation efforts based on established threat intelligence frameworks and industry best practices for mitigating driver-level vulnerabilities that compromise system integrity.