How severe is CVE-2023-20520?

CVE-2023-20520 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-20520 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-20520?

CVE-2023-20520 primarily affects Amd Epyc 72f3 Firmware. In total, 63 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2023-20520?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2023-20520 published?

CVE-2023-20520 was published on 2023-05-09 and last updated on 2026-06-17.

CVE-2023-20520

CVE-2023-20520 is a critical-severity vulnerability in Amd Epyc 72f3 Firmware with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Amd Epyc 72f3 Firmware
Published: 2023-05-09
Last modified: 2026-06-17

Description

Improper access control settings in ASP Bootloader may allow an attacker to corrupt the return address causing a stack-based buffer overrun potentially leading to arbitrary code execution.

Frequently asked questions

What is CVE-2023-20520?: Improper access control settings in ASP Bootloader may allow an attacker to corrupt the return address causing a stack-based buffer overrun potentially leading to arbitrary code execution.
How severe is CVE-2023-20520?: CVE-2023-20520 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-20520 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-20520?: CVE-2023-20520 primarily affects Amd Epyc 72f3 Firmware. In total, 63 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2023-20520?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-20520 published?: CVE-2023-20520 was published on 2023-05-09 and last updated on 2026-06-17.

References

https://www.amd.com/en/corporate/product-security/bulletin/AMD-SB-3001

Affected products (63)

cpe:2.3:o:amd:epyc_72f3_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7313_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7313p_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7343_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7373x_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_73f3_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7413_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7443_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7443p_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7453_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7473x_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_74f3_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7513_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7543_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7543p_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7573x_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_75f3_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7643_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7663_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7713_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7713p_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7763_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7773x_firmware:milanpi_1.0.0.5:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7232p_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7252_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7262_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7272_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7282_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7302_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7302p_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7352_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7402_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7402p_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7452_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7502_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7502p_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7532_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7542_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7552_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*
cpe:2.3:o:amd:epyc_7642_firmware:romepi_1.0.0.d:*:*:*:*:*:*:*

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