CVE-2021-46795

TEE OS crash via TOCTOU out-of-bounds read

Published Jan 10, 2023 · Updated Apr 9, 2025

TOCTOU in AMD Ryzen 3000 and 5000 Series Processors allows local users to crash the TEE OS through a compromised BIOS. The TEE OS checks a BIOS-controlled memory resource, then uses it after its state changes and reads beyond the intended bounds. Reaching the flaw requires low-privileged local access and prior BIOS compromise; the documented consequence is a service-interrupting TEE OS crash.

CVSS severity4.7
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

TOCTOU in AMD Ryzen 3000 and 5000 Series Processors allows local users to crash the TEE OS through a compromised BIOS. The TEE OS checks a BIOS-controlled memory resource, then uses it after its state changes and reads beyond the intended bounds. Reaching the flaw requires low-privileged local access and prior BIOS compromise; the documented consequence is a service-interrupting TEE OS crash.

The record

CVE
CVE-2021-46795
Published
Jan 10, 2023
Updated
Apr 9, 2025
Vendor
AMD
Product
AMD Ryzen 5000 Series Processors
Classifications
CWE-367, CAPEC-29, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 10, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 9, 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?

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  1. Affected versionversion=various

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

AMD · AMD Ryzen 5000 Series Processorsversion=various
AMD · AMD Ryzen 3000 Series Processorsversion=various

Published CVSS scores

4.7CISA-ADPCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/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.

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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 exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
CAPEC-29Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions
T1499Endpoint Denial of Service

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.

Technologies

Your stack

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Your stack

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