Description

HDD password plaintext is stored in a UEFI variable.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.2",
  "pubDate": "2026-09-03T13:04:10.943Z",
  "pubdate": "2026-09-03T13:04:10.943Z",
  "executiveSummary": "A critical security vulnerability exists where the plaintext hard disk drive (HDD) password is stored within a UEFI variable. This flaw represents an improper storage of sensitive credentials, violating security best practices for platform firmware and secure boot processes. The vulnerability allows unauthorized access to persistent data stored on encrypted drives, effectively bypassing the intended hardware-level protection mechanisms.\nThe impact is significant, as local attackers or malicious actors with limited system access can retrieve the cleartext password directly from the firmware's non-volatile storage. This credential exposure jeopardizes the confidentiality of the entire data partition, rendering drive encryption ineffective. The exploitation requires minimal technical complexity, as the UEFI interface provides standardized methods for reading variable data. Systems utilizing hardware-based full-disk encryption (FDE) relying on this firmware-level password management are at high risk of complete information disclosure. The vulnerability reflects a failure in the secure handling of authentication secrets during the Pre-EFI Initialization (PEI) or Driver Execution Environment (DXE) phases of the boot sequence, where secrets must ideally reside only in protected volatile memory (e.g., TPM-backed storage or secure enclaves).",
  "technicalDetails": "The root cause of this vulnerability is the improper implementation of persistent storage for security-critical authentication tokens within the UEFI firmware. UEFI variables, which are intended for configuration parameters and platform settings, are being misused to cache the cleartext HDD security password. These variables are stored in Non-Volatile RAM (NVRAM), typically residing in the SPI flash memory chip on the motherboard.\nThe vulnerability manifests because the firmware fails to utilize the Trusted Platform Module (TPM) for secure secret sealing or hardware-based key management. Instead, the plaintext password is written to the NVRAM during the user authentication process or the initial drive configuration phase. Because these UEFI variables are accessible by the operating system via the Runtime Services interface (e.g., GetVariable), any user-space process with sufficient privileges or an attacker with local access to the kernel can query the firmware environment to dump these sensitive values.\nThe attack flow follows a predictable pattern: 1) The attacker gains local execution context on the target host. 2) The attacker interacts with the UEFI Runtime Services, specifically the 'GetVariable' function. 3) By specifying the correct GUID and variable name associated with the HDD password, the attacker retrieves the raw, plaintext credential from the firmware's flash memory. 4) Once the plaintext password is acquired, the attacker can present it to the drive controller upon a cold boot or bypass the firmware-level password prompt, gaining full access to the encrypted sectors of the storage device.\nThis vulnerability persists because there is no cryptographic binding or obfuscation applied to the stored password. The data is stored in the clear, making it retrievable even if the operating system's integrity is compromised. Furthermore, because these variables are often backed up or synchronized by certain system management software or firmware update utilities, the exposure radius may extend to system recovery environments or off-platform firmware images. The lack of hardware-backed protection or access control lists (ACLs) on these specific UEFI variables means that any software running with system or administrative privileges can bypass intended security boundaries. Post-exploitation, the attacker gains the ability to decrypt the physical storage medium offline, effectively neutralizing the intended protection of the hardware encryption."
}