CVE-2021-26354

Memory integrity loss via unchecked ASP syscall

Published May 9, 2023 · Updated Jan 28, 2025

Memory corruption in the Secure Processor of affected AMD processors allows local users to zero arbitrary memory through a crafted system call. The ASP performs insufficient bounds checking on a system call issued from a compromised AMD bootloader, allowing attacker-selected memory values to be initialized to zero. Exploitation requires low local privileges and control of the AMD bootloader, and the documented consequence is loss of memory integrity.

CVSS severity5.5
Medium
EPSS probability0.18%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in the Secure Processor of affected AMD processors allows local users to zero arbitrary memory through a crafted system call. The ASP performs insufficient bounds checking on a system call issued from a compromised AMD bootloader, allowing attacker-selected memory values to be initialized to zero. Exploitation requires low local privileges and control of the AMD bootloader, and the documented consequence is loss of memory integrity.

The record

CVE
CVE-2021-26354
Published
May 9, 2023
Updated
Jan 28, 2025
Vendor
AMD
Product
Ryzen 5000 Series Mobile Processors with Radeon Graphics (Lucienne)
Classifications
CWE-120
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 28, 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?

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 privilegesauthenticated

What is affected?

AMD · Ryzen 5000 Series Mobile Processors with Radeon Graphics (Lucienne)version=various
Advanced Micro Devices, Inc. · 3rd Gen AMD EPYC Processorsversion=various
Advanced Micro Devices, Inc. · AMD Ryzen 5000 Series Desktop Processors with Radeon Graphics (Cezanne)version=Various
Advanced Micro Devices, Inc. · AMD Ryzen Threadripper 2000 Series Processors (Colfax)version=various
AMD · Ryzen 2000 Series Mobile Processors (Raven Ridge, FP5)version=various
Advanced Micro Devices, Inc. · AMD Ryzen Threadripper 3000 Series Processors (Castle Peak)version=various
AMD · Athlon 3000 Series Mobile Processors with Radeon Graphics (Pollock)version=various
AMD · Athlon 3000 Series Mobile Processors with Radeon Graphics (Dali/Dali ULP)version=various
Advanced Micro Devices, Inc. · AMD Ryzen 3000 Series Mobile Processors with Radeon Graphics (Picasso)version=various
AMD · Ryzen 2000 Series Desktop Processors (Raven Ridge, AM4)version=various
Advanced Micro Devices, Inc. · AMD Ryzen 5000 Series Desktop Processors (Vermeer)version=various
AMD · Ryzen 3000 Series Mobile Processors with Radeon Graphics (Renoir)version=various
AMD · Ryzen 5000 Series Mobile Processors with Radeon Graphics (Cezanne)version=various
Advanced Micro Devices, Inc. · 2nd Gen AMD EPYC Processorsversion=various
Advanced Micro Devices, Inc. · AMD Ryzen Threadripper PRO Processors (Castle Peak)version=various
Advanced Micro Devices, Inc. · AMD Ryzen Threadripper PRO 3000WX Series Processors (Chagall)version=various
Advanced Micro Devices, Inc. · AMD Ryzen 2000 Series Desktop Processors (Pinnacle Ridge)version=various
Advanced Micro Devices, Inc. · AMD Ryzen 3000 Series Desktop Processors (Matisse)version=various

Published CVSS scores

5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

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 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

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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