AMD Server Vulnerabilities – May 2023  

Bulletin ID: AMD-SB-3001
Potential Impact: Varies by CVE, see descriptions below
Severity: Varies by CVE, see descriptions below

Summary

Potential vulnerabilities in the AMD Secure Processor (ASP), AMD System Management Unit (SMU), AMD Secure Encrypted Virtualization (SEV) and other platform components were discovered, and mitigations have been provided in AMD EPYC™ AGESA™ PI packages.

Affected Products

AMD EPYC™ Servers

CVE Details

CVE

Severity

Description

CVE-2021-46769

 

High

Insufficient syscall input validation in the ASP Bootloader may allow a privileged attacker to execute arbitrary DMA copies, which can lead to code execution.

CVE-2021-26354

 

Medium

Insufficient bounds checking in ASP may allow an attacker to issue a system call from a compromised ABL which may cause arbitrary memory values to be initialized to zero, potentially leading to a loss of integrity.

CVE-2021-26356

 

Medium

A TOCTOU in ASP bootloader may allow an attacker to tamper with the SPI ROM following data read to memory potentially resulting in S3 data corruption and information disclosure.

CVE-2021-26371

 

Medium

A compromised or malicious ABL or UApp could send a SHA256 system call to the bootloader, which may result in exposure of ASP memory to userspace, potentially leading to information disclosure.

CVE-2021-26379

 

Medium

Insufficient input validation of mailbox data in the SMU may allow an attacker to coerce the SMU to corrupt SMRAM, potentially leading to a loss of integrity and privilege escalation.

CVE-2021-26397

Medium

Insufficient address validation, may allow an attacker with a compromised ABL and UApp to corrupt sensitive memory locations potentially resulting in a loss of integrity or availability.

CVE-2021-26406

 

Medium

Insufficient validation in parsing Owner's Certificate Authority (OCA) certificates in SEV (AMD Secure Encrypted Virtualization) and SEV-ES user application can lead to a host crash potentially resulting in denial of service.

CVE-2021-46756

 

Medium

Insufficient validation of inputs in SVC_MAP_USER_STACK in the ASP (AMD Secure Processor) bootloader may allow an attacker with a malicious Uapp or ABL to send malformed or invalid syscall to the bootloader resulting in a potential denial of service and loss of integrity.

CVE-2021-46763

 

Medium

Insufficient input validation in the SMU may enable a privileged attacker to write beyond the intended bounds of a shared memory buffer potentially leading to a loss of integrity.

CVE-2021-46764

 

Medium

Improper validation of DRAM addresses in SMU may allow an attacker to overwrite sensitive memory locations within the ASP potentially resulting in a denial of service.

CVE-2021-46775

Medium

Improper input validation in ABL may enable an attacker with physical access, to perform arbitrary memory overwrites, potentially leading to a loss of integrity and code execution.

CVE-2022-23818

Medium

Insufficient input validation on the model specific register: VM_HSAVE_PA may potentially lead to loss of SEV-SNP guest memory integrity.

CVE-2021-46762

Medium

Insufficient input validation in the SMU may allow an attacker to corrupt SMU SRAM potentially leading to a loss of integrity or denial of service.

CVE-2023-20524

Medium

An attacker with a compromised ASP could possibly send malformed commands to an ASP on another CPU, resulting in an out of bounds write, potentially leading to a loss a loss of integrity.

CVE-2023-20520

Medium

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.

Specific CVSS scores may change subject to your implementation. We encourage you to calculate CVSS scores independently for your system.

 

Mitigation

The AGESA™ versions listed below have been released to the Original Equipment Manufacturers (OEM) to help mitigate these issues. Please refer to your OEM for the BIOS update specific to your product.

CVE

1st Gen AMD EPYC™ Processors

2nd Gen AMD EPYC™ Processors

3rd Gen AMD EPYC™
Processors

4th Gen AMD EPYC™
Processors

Minimum version to mitigate all listed CVEs

NaplesPI 1.0.0.J

RomePI 1.0.0.E

MilanPI 1.0.0.9

"Genoa"
(Product not impacted)

CVE-2021-26354

N/A

RomePI 1.0.0.C

MilanPI 1.0.0.4

N/A

CVE-2021-26356

NaplesPI 1.0.0.H

RomePI 1.0.0.D

MilanPI 1.0.0.6

N/A

CVE-2021-26371

NaplesPI 1.0.0.H

RomePI 1.0.0.D

MilanPI 1.0.0.6

N/A

CVE-2021-26379

N/A

RomePI 1.0.0.E

MilanPI 1.0.0.9

N/A

CVE-2021-26397

N/A

N/A

MilanPI 1.0.0.9

N/A

CVE-2021-26406

NaplesPI 1.0.0.E

RomePI 1.0.0.A

N/A

N/A

CVE-2021-46756

NaplesPI 1.0.0.J

RomePI 1.0.0.E

MilanPI 1.0.0.9

N/A

CVE-2021-46762

N/A

RomePI 1.0.0.E

MilanPI 1.0.0.9

N/A

CVE-2021-46763

N/A

RomePI 1.0.0.E

MilanPI 1.0.0.9

N/A

CVE-2021-46764

N/A

RomePI 1.0.0.E

MilanPI 1.0.0.9

N/A

CVE-2021-46769

N/A

RomePI 1.0.0.E

MilanPI 1.0.0.9

N/A

CVE-2021-46775

N/A

RomePI 1.0.0.E

MilanPI 1.0.0.9

N/A

CVE-2022-23818

N/A

N/A

MilanPI 1.0.0.9

N/A

CVE-2023-20520

NaplesPI 1.0.0.H

RomePI 1.0.0.D

MilanPI 1.0.0.5

N/A

CVE-2023-20524

N/A

RomePI 1.0.0.C

 

MilanPI 1.0.0.5

 

N/A

 

SEV TABLE

CVE ID

SEV

SEV-ES

SEV-SNP

CVE-2021-26354

Y

Y

Y

CVE-2021-26356

N/A

N/A

N/A

CVE-2021-26371

N

N

Y

CVE-2021-26379

N

Y

Y

CVE-2021-26397

N

Y

Y

CVE-2021-26406

Y

Y

N

CVE-2021-46756

Y

Y

Y

CVE-2021-46763

N

N

Y

CVE-2021-46764

Y

Y

Y

CVE-2021-46769

Y

Y

Y

CVE-2021-46762

Y

Y

Y

CVE-2021-46775

Y

Y

Y

CVE-2022-23818

N

N

Y

CVE-2023-20520

N

N

N/A

CVE-2023-20524

N

N

N

 

SEV applicability:

Name

SEV

SEV-ES

SEV-SNP

Naples

Applicable

Applicable

Not Applicable

Rome

Applicable

Applicable

Not Applicable

Milan

Applicable

Applicable

Applicable

Genoa

Applicable

Applicable

Applicable

Trento

Not Applicable

Not Applicable

Not Applicable

 

Acknowledgement

  • Internally reported: CVE-2021-26354, CVE-2021-26356, CVE-2021-26371, CVE-2021-26379, CVE-2021-26406, CVE-2021-46756, CVE-2021-46763, CVE-2021-46764, CVE-2021-46769, CVE-2021-46762, CVE-2023-20524, CVE-2021-26397, CVE-2022-23818, CVE-2021-46755, CVE-2022-23818   

 

Revisions

Revision Date Description
5/9/2023 Initial publication 

 

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