CVE Intelligence
High

CVE-2021-38489 — HDD Password Stored In Plaintext

HDD password plaintext is stored in a UEFI variable.

Published Sep 3, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Insyde

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
—
No EPSS score.
Affects
Insyde Software
InsydeH2O
CVSS base
8.2
High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Insyde Software InsydeH2O).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Insyde Software InsydeH2O version See in the Solution Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
8.2 CVSS 3.1 High 1.5 6.0 8338d8cb-57f7-4252-abc0-96fd13e98d21 via NIST National Vulnerability Database
8.2 CVSS 3.1 High — — Insyde via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H (score shown at the top: 8338d8cb-57f7-4252-abc0-96fd13e98d21)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-256

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · insyde software/insydeh2o
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 8.2
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Undergoing Analysis
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 3, 2026 · Insyde

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

1 on the record

Elsewhere on this site

Insyde Software
every CVE for this vendor
CWE-256
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-6485 UEFI BIOS embedded Shell can be used to bypass Secure Boot Sep 9, 2026
  • CVE-2026-12855 H19WMIHandlerSmm: unvalidated memory boundary could result in arbitrary code execution. Sep 9, 2026
  • CVE-2021-43613 SysPasswordDxe: Password hashes are exposed in runtime UEFI variables, leading to escalation of privilege Sep 3, 2026
  • CVE-2021-43614 VariableEditSmm: Error checking of UEFI variables could cause buffer overflow, leading to code execution Sep 3, 2026
  • CVE-2026-9805 FMTSWriteUseIntelLib: FMTS SMM IHISI Buffer Overflow Aug 26, 2026
  • CVE-2025-10451 H19Int15CallbackSmm: SMM memory corruption vulnerability in combined DXE/SMM (SMRAM write) Dec 11, 2025

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No FIRST EPSS score.
  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2021-38489 is "HDD Password Stored In Plaintext", rated High. It affects InsydeH2O (Insyde Software); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.2 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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