CVE-2026-71350 in Windows
Summary
by MITRE • 09/09/2026
Heap-based buffer overflow in Windows Spaceport.sys allows an unauthorized attacker to execute code with a physical attack.
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Analysis
by VulDB Data Team • 09/09/2026
The vulnerability identified within the Windows Spaceport.sys driver represents a critical heap-based buffer overflow condition that fundamentally compromises system integrity through direct hardware interaction. This specific flaw resides in the kernel-mode component responsible for managing space port devices, which are typically associated with storage controllers and other peripheral interfaces connected via high-speed buses such as PCIe or Thunderbolt. The core technical deficiency involves an improper validation of input data lengths before they are copied into a dynamically allocated heap buffer. When an attacker provides crafted input that exceeds the expected bounds, the driver fails to perform adequate boundary checks, resulting in memory corruption where adjacent heap metadata or critical kernel structures are overwritten with maliciously controlled data. This type of vulnerability is classically categorized under CWE-122, which denotes a heap-based buffer overflow, and it exploits the lack of rigorous input sanitization within privileged system code.
The operational impact of this flaw is severe due to its potential for arbitrary code execution at ring 0 privilege level. Because Spaceport.sys operates with kernel-level access rights, successfully exploiting this memory corruption allows an attacker to gain complete control over the operating system. This includes the ability to install rootkits, dump sensitive credentials from memory, disable security software, and modify critical system files without detection. The requirement for a physical attack vector significantly narrows the scope of potential adversaries but increases the severity of each successful exploitation event. Physical access implies that an attacker has direct connectivity to the machine's ports or internal buses, allowing them to utilize specialized hardware tools such as DMA (Direct Memory Access) attacks via external devices like Thunderbolt dongles or custom FPGA-based exploit kits. This aligns with MITRE ATT&CK technique T1055.012, which covers Direct Memory Access techniques, and highlights the risk associated with untrusted peripheral connections in high-security environments where physical isolation is not strictly enforced.
Mitigation strategies for this vulnerability must address both software patching and hardware configuration controls. The primary defense involves applying the latest security updates provided by Microsoft that correct the input validation logic within Spaceport.sys to ensure all buffer operations respect allocated memory limits. In addition to software remediation, organizations should enforce strict physical access policies to prevent unauthorized individuals from connecting external devices directly to system ports. For environments where remote or unattended operation is required but physical security cannot be guaranteed, disabling unused high-speed peripheral interfaces through BIOS/UEFI settings can reduce the attack surface. Furthermore, enabling hardware-enforced stack and heap protections such as Kernel Address Space Layout Randomization (KASLR) and Data Execution Prevention (DEP) can mitigate exploitation attempts by making it significantly more difficult for attackers to predict memory layouts and execute injected code, although these measures serve as compensating controls rather than definitive fixes for the underlying coding error.