CVE-2021-38489: H2O HDD password stored in plaintext

CISO Take

This vulnerability (CWE-256) is in InsydeH2O, a UEFI/BIOS firmware implementation licensed to many PC and edge-device OEMs — it stores the hard-disk password in plaintext inside a UEFI variable instead of protecting it, letting a local attacker with high privileges read the credential and unlock or clone the drive. This is a firmware supply-chain issue, not an AI/ML software vulnerability; its tagging under 'ml_library' in this dataset appears to be a miscategorization, since InsydeH2O is not a pip package or ML library and none of the tracked AI/ML packages are implicated. The practical risk is narrow: exploitation requires local access plus high privileges (AV:L/PR:H), there is no public exploit or Nuclei template, it is not in CISA KEV, and the EPSS score (0.00121) indicates very low real-world exploitation probability — the 'top 98%' percentile figure supplied for this CVE is inconsistent with that low score and should not be relied on to justify urgency. For any organization running AI workloads on physical or edge hardware where InsydeH2O firmware is present (laptops, edge inference boxes, some server BMCs), the action is to check with the OEM for a firmware update referencing this advisory (Insyde SA-2022025) and, as a workaround, avoid relying on the built-in HDD password feature for data-at-rest protection on affected devices, using full-disk encryption with a TPM-backed key instead. This does not warrant a breaking alert; treat it as routine firmware patch hygiene rather than an AI-specific threat.

Sources:NVDEPSSOpenSSF

What is the risk?

Low-to-moderate risk in practice despite the High CVSS base score (8.2). The vector requires local access and high privileges (AV:L/AC:L/PR:H/UI:N), meaning an attacker already needs significant foothold on the device before this flaw adds value — it's an escalation/credential-disclosure primitive, not an initial-access vector. No public exploit, no Nuclei template, not in CISA KEV, and EPSS (0.00121) indicates very low predicted exploitation likelihood in the wild. This is a hardware/firmware-layer issue affecting InsydeH2O UEFI implementations broadly, not an AI/ML-specific vulnerability — the 'ml_library' AI category assigned to this CVE does not reflect its actual scope.

How does the attack unfold?

Initial local foothold

Attacker already has high-privilege local access to a device running vulnerable InsydeH2O UEFI firmware.

Credential extraction

Attacker reads the plaintext HDD password stored in the UEFI variable.

Drive unlock

Attacker uses the extracted password to unlock the HDD in place or on another machine.

Data access impact

Attacker gains unrestricted read access to the drive's contents, including any locally stored sensitive files.

AML.T0037

Initial local foothold

Attacker already has high-privilege local access to a device running vulnerable InsydeH2O UEFI firmware.

Credential extraction

Attacker reads the plaintext HDD password stored in the UEFI variable.

Drive unlock

Attacker uses the extracted password to unlock the HDD in place or on another machine.

Data access impact

Attacker gains unrestricted read access to the drive's contents, including any locally stored sensitive files.

AML.T0037

What systems are affected?

Package	Ecosystem	Vulnerable Range	Patched
H2O	pip	—	No patch
7.5KOpenSSF 5.727 dependentsPushed 9d ago8% patched~0d to patchFull package profile →

Do you use H2O? You're affected.

How severe is it?

CVSS 3.1

8.2 / 10

EPSS

0.2%

chance of exploitation in 30 days

Higher than 5% of all CVEs

Source: EPSS v3 — FIRST.org

Exploitation Status

No known exploitation

Sophistication

Moderate

What is the attack surface?

AVLocal

ACLow

PRHigh

UINone

SChanged

CHigh

IHigh

AHigh

What should I do?

1 step

1) Check with your device OEM/vendor for a firmware update that addresses Insyde advisory SA-2022025 (InsydeH2O UEFI). 2) Do not rely on the ATA/UEFI HDD password as your primary data-at-rest control on affected hardware; use OS-level full-disk encryption (BitLocker, LUKS) with a TPM-bound key instead. 3) Restrict physical and local-admin access to devices storing sensitive AI artifacts (models, datasets, API keys) as a general control, since this flaw requires high local privileges to exploit. 4) There is no detection signature for this class of firmware issue via standard EDR/log monitoring — remediation is firmware-update driven, not detection-driven.

What does CISA's SSVC say?

DecisionTrack

Exploitationnone

AutomatableNo

Technical Impacttotal

Source: CISA Vulnrichment (SSVC v2.0). Decision based on the CISA Coordinator decision tree.

How is it classified?

Data LeakagePrivacy ViolationInference

Which compliance frameworks are affected?

This CVE is relevant to:

NIST AI RMF

GOVERN-4.1-Third-party and supply chain risk management

Frequently Asked Questions

What is CVE-2021-38489?

This vulnerability (CWE-256) is in InsydeH2O, a UEFI/BIOS firmware implementation licensed to many PC and edge-device OEMs — it stores the hard-disk password in plaintext inside a UEFI variable instead of protecting it, letting a local attacker with high privileges read the credential and unlock or clone the drive. This is a firmware supply-chain issue, not an AI/ML software vulnerability; its tagging under 'ml_library' in this dataset appears to be a miscategorization, since InsydeH2O is not a pip package or ML library and none of the tracked AI/ML packages are implicated. The practical risk is narrow: exploitation requires local access plus high privileges (AV:L/PR:H), there is no public exploit or Nuclei template, it is not in CISA KEV, and the EPSS score (0.00121) indicates very low real-world exploitation probability — the 'top 98%' percentile figure supplied for this CVE is inconsistent with that low score and should not be relied on to justify urgency. For any organization running AI workloads on physical or edge hardware where InsydeH2O firmware is present (laptops, edge inference boxes, some server BMCs), the action is to check with the OEM for a firmware update referencing this advisory (Insyde SA-2022025) and, as a workaround, avoid relying on the built-in HDD password feature for data-at-rest protection on affected devices, using full-disk encryption with a TPM-backed key instead. This does not warrant a breaking alert; treat it as routine firmware patch hygiene rather than an AI-specific threat.

Is CVE-2021-38489 actively exploited?

No confirmed active exploitation of CVE-2021-38489 has been reported, but organizations should still patch proactively.

How to fix CVE-2021-38489?

1) Check with your device OEM/vendor for a firmware update that addresses Insyde advisory SA-2022025 (InsydeH2O UEFI). 2) Do not rely on the ATA/UEFI HDD password as your primary data-at-rest control on affected hardware; use OS-level full-disk encryption (BitLocker, LUKS) with a TPM-bound key instead. 3) Restrict physical and local-admin access to devices storing sensitive AI artifacts (models, datasets, API keys) as a general control, since this flaw requires high local privileges to exploit. 4) There is no detection signature for this class of firmware issue via standard EDR/log monitoring — remediation is firmware-update driven, not detection-driven.

What systems are affected by CVE-2021-38489?

This vulnerability affects the following AI/ML architecture patterns: on-device/edge inference (hardware layer, indirect).

What is the CVSS score for CVE-2021-38489?

CVE-2021-38489 has a CVSS v3.1 base score of 8.2 (HIGH). The EPSS exploitation probability is 0.16%.

What is the AI security impact?

Affected AI Architectures

on-device/edge inference (hardware layer, indirect)

Compliance Controls Affected

NIST AI RMF: GOVERN-4.1

What are the technical details?

Original Advisory

HDD password plaintext is stored in a UEFI variable.

Exploitation Scenario

An attacker who has already obtained a foothold with high local privileges on a device running vulnerable InsydeH2O firmware (e.g., via a prior compromise, insider access, or physical access to a stolen laptop) reads the UEFI variable containing the plaintext HDD password. They use this password to unlock the drive — either in place or after removing it and connecting it to another machine — and gain unrestricted access to its contents, including any locally cached AI model files, training data, or service credentials, bypassing the intended password-based drive lock.

Weaknesses (CWE)

CWE-256Plaintext Storage of a Password

CWE-256 — Plaintext Storage of a Password: The product stores a password in plaintext within resources such as memory or files.

[Architecture and Design] Avoid storing passwords in easily accessible locations.
[Architecture and Design] Consider storing cryptographic hashes of passwords as an alternative to storing in plaintext.

Source: MITRE CWE corpus.