Description

Heap-based buffer overflow in Windows Universal Disk Format File System Driver (UDFS) allows an unauthorized attacker to execute code with a physical attack.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.8",
  "pubDate": "2026-08-11T17:18:19.490Z",
  "pubdate": "2026-08-11T17:18:19.490Z",
  "executiveSummary": "A heap-based buffer overflow vulnerability has been identified within the Windows Universal Disk Format File System Driver (UDFS). This memory corruption flaw allows an unauthorized local attacker capable of performing a physical attack to achieve arbitrary code execution within the context of the affected operating system. The vulnerability stems from improper bounds checking or memory allocation handling during the parsing of file system structures processed by the UDFS driver. Successful exploitation of this vulnerability compromises the integrity, confidentiality, and availability of the host system, granting the attacker low-level system access. Because the attack vector relies on physical access, the threat model typically encompasses scenarios where an adversary connects a maliciously crafted storage medium, such as an optical disc or specialized USB device formatted with UDFS, to the target machine. Consequently, the operating system attempts to mount and parse the file system using the vulnerable driver, triggering the heap overflow condition during the initial parsing phase. Organizations must apply applicable security updates provided by the vendor to remediate this driver-level flaw and restrict physical access to sensitive workstations and servers to mitigate potential risks.",
  "technicalDetails": "The vulnerability resides in the Windows Universal Disk Format File System Driver (UDFS), a kernel-mode component responsible for interpreting and managing Universal Disk Format (UDF) file systems on storage media. The root cause of the issue is a heap-based buffer overflow, which occurs when the driver allocates an insufficient amount of heap memory or fails to properly validate the size parameters of incoming data structures contained within the UDFS file system metadata, such as descriptors or file identifiers. When the operating system mounts the storage medium, the UDFS driver reads these crafted metadata structures into kernel heap memory. Due to the lack of stringent bounds checking during the copy or parsing operation, the input data exceeds the boundaries of the allocated heap buffer, resulting in a heap-based buffer overflow. The attack flow begins when an unauthorized attacker leverages a physical attack vector by inserting a maliciously formatted UDF storage medium into the target machine's optical or USB drive. The Windows kernel automatically invokes the UDFS driver to parse the file system layout upon detection of the medium. As the driver processes the malformed structures, the heap overflow corrupts adjacent heap memory chunks, metadata, or function pointers. By carefully crafting the size and content of the malicious structures, an attacker can manipulate the heap layout to achieve arbitrary code execution in kernel mode. Given that the UDFS driver operates at a high privilege level (Ring 0), successful exploitation grants the attacker full control over the operating system kernel, enabling them to bypass security controls, install persistent rootkits, or execute arbitrary payload behavior. The exploitation requires physical access to the target system and local interaction to mount the crafted storage medium, with no network exposure required as the attack surface is strictly local and hardware-dependent."
}