CVE-2021-0156Known exploitation

Local privilege escalation via improper input validation

Published Feb 9, 2022 · Updated May 5, 2025

Improper input validation in Intel(R) Processors firmware allows authenticated local users to enable privilege escalation via local access. Intel identifies processor firmware as the affected locus but does not disclose which input or validation operation permits the escalation. Access requires an authenticated local user, and the resulting impact is privilege escalation affecting confidentiality, integrity, and availability.

CVSS severity7.8
High
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Intel(R) Processors firmware allows authenticated local users to enable privilege escalation via local access. Intel identifies processor firmware as the affected locus but does not disclose which input or validation operation permits the escalation. Access requires an authenticated local user, and the resulting impact is privilege escalation affecting confidentiality, integrity, and availability.

The record

CVE
CVE-2021-0156
Published
Feb 9, 2022
Updated
May 5, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 9, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 2025Exploitation reportedNo exploitation observed in CISA SSVC assessment
  3. May 5, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.6NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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