CVE-2021-46774

Privilege escalation via unvalidated ABL DRAM writes

Published Nov 14, 2023 · Updated Oct 11, 2024

Insufficient input validation in AMD processor ABL firmware allows attackers to write arbitrary DRAM and escalate privileges. ABL accepts a boot image without adequately validating attacker-controlled input before using it to issue DRAM writes. Exploitation requires privileged ability to write the boot image; successful use enables code execution and privilege escalation across the platform firmware trust boundary.

CVSS severity6.7
Medium
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient input validation in AMD processor ABL firmware allows attackers to write arbitrary DRAM and escalate privileges. ABL accepts a boot image without adequately validating attacker-controlled input before using it to issue DRAM writes. Exploitation requires privileged ability to write the boot image; successful use enables code execution and privilege escalation across the platform firmware trust boundary.

The record

CVE
CVE-2021-46774
Published
Nov 14, 2023
Updated
Oct 11, 2024
Vendor
AMD
Product
4th Gen AMD EPYC Processors
Classifications
T1068
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Nov 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 11, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=various

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

AMD · 4th Gen AMD EPYC Processorsversion=various
AMD · AMD Ryzen Threadripper PRO 3000WX Series Processors (Castle Peak WS)version=various
AMD · 2nd Gen AMD EPYC Processorsversion=various
AMD · AMD Ryzen Threadripper 3000 Series Processors (Castle Peak HEDT)version=various
AMD · AMD Ryzen Embedded 5000 Seriesversion=various
AMD · AMD Ryzen 5000 Series Desktop Processors (Vermeer)version=various
AMD · 3rd Gen AMD EPYC Processorsversion=various
AMD · AMD EPYC Embedded 7002 Series Processorsversion=various
AMD · 1st Gen AMD EPYC Processorsversion=various
AMD · AMD Ryzen 3000 Series Desktop Processors (Matisse)version=various
AMD · AMD EPYC Embedded 7003 Series Processorsversion=various
AMD · AMD EPYC Embedded 3000 Series Processorsversion=various

Published CVSS scores

6.7AMDCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:L/I:H/A:L

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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.

Technologies

Your stack

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Your stack

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