Security Resilience

CVE-2023-20521

Race Condition in Amd Epyc 7001 Firmware ≤ naplespi_1.0.0.h

Race Condition
Published
14 November 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 3.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:P/AC:H/PR:H/UI:N/S:C/C:L/I:N/A:L
EPSS Score 0.0026 17th percentile
Risk Priority 26 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-20521 is a low-severity Time-of-check Time-of-use (TOCTOU) Race Condition (CWE-367) vulnerability in Amd Epyc 7001 Firmware. Its CVSS base score is 3.3 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Security Account Manager (T1003.002); ranked at the 17th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

TOCTOU in the ASP Bootloader may allow an attacker with physical access to tamper with SPI ROM records after memory content verification, potentially leading to loss of confidentiality or a denial of service.

CWE(s)
CWE-367

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003.002 Security Account Manager Credential Access
Adversaries may attempt to extract credential material from the Security Account Manager (SAM) database either through in-memory techniques or through the Windows Registry where the SAM database is stored.
attack.mitre.org →
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
attack.mitre.org →
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
attack.mitre.org →
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
attack.mitre.org →
T1016 System Network Configuration Discovery Discovery
Adversaries may look for details about the network configuration and settings, such as IP and/or MAC addresses, of systems they access or through information discovery of remote systems.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-20578Same product: Amd Epyc 7001
CVE-2023-20523Same product: Amd Epyc 7232P
CVE-2023-31324Same vendor: Amd
CVE-2023-20548Same vendor: Amd
CVE-2023-20526Same product: Amd Epyc 7001
CVE-2023-20592Same product: Amd Epyc 7001
CVE-2023-20520Same product: Amd Epyc 7232P
CVE-2023-20527Same product: Amd Epyc 7001
CVE-2023-20524Same product: Amd Epyc 7232P
CVE-2023-20529Same product: Amd Epyc 7232P

Affected Assets

amd
epyc 7001 firmware
≤ naplespi_1.0.0.h
amd
epyc 7251 firmware
≤ naplespi_1.0.0.h
amd
epyc 7261 firmware
≤ naplespi_1.0.0.h
amd
epyc 7281 firmware
≤ naplespi_1.0.0.h
amd
epyc 7301 firmware
≤ naplespi_1.0.0.h
amd
epyc 7351 firmware
≤ naplespi_1.0.0.h
amd
epyc 7351p firmware
≤ naplespi_1.0.0.h
amd
epyc 7371 firmware
≤ naplespi_1.0.0.h
amd
epyc 7401 firmware
≤ naplespi_1.0.0.h
amd
epyc 7401p firmware
≤ naplespi_1.0.0.h
+83 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V15.4.2
  • V17.2.6

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

AU-8 Time Stamps
addresses: CWE-367

Timestamps meeting UTC or offset standards help identify TOCTOU issues through precise chronological reconstruction of check/use operations.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 partial match
blocks

Secure SDLC practices directly include coding standards and reviews that prevent TOCTOU race conditions.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References