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AMD Server Vulnerabilities – Nov 2023

Bulletin ID: AMD-SB-3002
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), AMD Secure Encrypted Virtualization – Secure Nested Paging (SEV-SNP) and other platform components were discovered and mitigations have been provided in AMD EPYC™ Platform Initialization (PI) firmware packages.

Please refer to your OEM for the BIOS update specific to your product.

CVE Details

Refer to Glossary for explanation of terms

CVE

Severity

CVE Description

CVE-2022-23820

High

Failure to validate the AMD SMM communication buffer may allow an attacker to corrupt the SMRAM potentially leading to arbitrary code execution.

CVE-2021-46774

Medium

Insufficient input validation in ABL may enable a privileged attacker with the ability to write to the boot image to perform arbitrary DRAM writes, potentially resulting in code execution and privilege escalation.

CVE-2023-20519

Medium

A Use-After-Free vulnerability in the management of an SNP guest context page may allow a malicious hypervisor to masquerade as the guest's migration agent resulting in a potential loss of guest integrity.

CVE-2023-20533

Medium

Insufficient DRAM address validation in System Management Unit (SMU) may allow an attacker to read/write from/to an invalid DRAM address, potentially resulting in denial-of-service.

CVE-2023-20566

Medium

Improper address validation in ASP with SNP enabled may potentially allow an attacker to compromise guest memory integrity.

CVE-2021-26345

Low

Failure to validate the value in APCB may allow a privileged attacker to tamper with the APCB token to force an out-of-bounds memory read potentially resulting in a denial of service.

CVE-2021-46766

Low

Improper clearing of sensitive data in the ASP Bootloader may expose secret keys to a privileged attacker accessing ASP SRAM, potentially leading to a loss of confidentiality.

CVE-2022-23830

Low

SMM configuration may not be immutable, as intended, when SNP is enabled resulting in a potential limited loss of guest memory integrity.

CVE-2023-20521

Low

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.

CVE-2023-20526

Low

Insufficient input validation in the ASP Bootloader may enable a privileged attacker with physical access to expose the contents of ASP memory potentially leading to a loss of confidentiality.

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

Affected Products

N/A

Mitigation

1st Gen AMD EPYC™ Processors formerly codenamed "Naples"

AMD recommends updating to the Platform Initialization (PI) firmware version indicated below.
There are no other available mitigation options.

CPUIDs

Mitigation Option 1

Mitigation Option 2

0x00800F12

Platform Initialization (PI)
(Requires FW flash)

μcode
(Hot loadable)

SEV FW

Minimum firmware versions to mitigate all applicable CVEs

NaplesPI 1.0.0.K
(2023-04-27)

N/A

N/A

CVE-2022-23820

7.5 (High)

Not affected

N/A

N/A

CVE-2021-46774

6.6 (Medium)

NaplesPI 1.0.0.K
(2023-04-27)

N/A

N/A

CVE-2023-20533

6.1 (Medium)

Not affected

N/A

N/A

CVE-2023-20519

6.0 (Medium)

Not affected

N/A

N/A

CVE-2023-20566

5.3 (Medium)

Not affected

N/A

N/A

CVE-2023-20521

3.3 (Low)

NaplesPI 1.0.0.H
(2021-12-14)

N/A

N/A

CVE-2021-46766

2.5 (Low)

Not affected

N/A

N/A

CVE-2023-20526

1.9 (Low)

NaplesPI 1.0.0.H
(2021-12-14)

N/A

N/A

CVE-2022-23830

1.9 (Low)

Not affected

N/A

N/A

CVE-2021-26345

1.9 (Low)

Not affected

N/A

N/A

 

2nd Gen AMD EPYC™ Processors formerly codenamed "Rome"

AMD recommends updating to the Platform Initialization (PI) firmware version indicated below.There are no other available mitigation options.

CPUIDs

Mitigation Option 1

Mitigation Option 2

0x00830F10h

Platform Initialization (PI)
(Requires FW flash)

μcode
(Hot loadable)

SEV FW

Minimum firmware versions to mitigate all applicable CVEs below

RomePI 1.0.0.G
(2023-05-05)

N/A

N/A

CVE-2022-23820

7.5 (High)

Not affected

N/A

N/A

CVE-2021-46774

6.6 (Medium)

RomePI 1.0.0.G
(2023-05-05)

N/A

N/A

CVE-2023-20533

6.1 (Medium)

RomePI 1.0.0.D
(2021-12-16)

N/A

N/A

CVE-2023-20519

6.0 (Medium)

Not affected

N/A

N/A

CVE-2023-20566

5.3 (Medium)

Not affected

N/A

N/A

CVE-2023-20521

3.3 (Low)

RomePI 1.0.0.D
(2021-12-16)

N/A

N/A

CVE-2021-46766

2.5 (Low)

Not affected

N/A

N/A

CVE-2023-20526

1.9 (Low)

RomePI 1.0.0.D
(2021-12-16)

N/A

N/A

CVE-2022-23830

1.9 (Low)

Not affected

N/A

N/A

CVE-2021-26345

1.9 (Low)

RomePI 1.0.0.F
(2022-10-28)

N/A

N/A

 

3rd Gen AMD EPYC™ Processors formerly codenamed “Milan

AMD recommends updating to the Platform Initialization (PI) firmware version indicated below. For some CVEs, there may be alternative mitigation options provided as Mitigation Option 2, including microcode and/or other patches.

CPUIDs

Mitigation Option 1

Mitigation Option 2

TCB Values
for
SNP Attestation

0x00A00F11

0x00A00F12

Platform Initialization (PI)
(Requires FW flash)

μcode
(Hot loadable)

 

SEV FW
(Hot loadable)

 TCB[SNP]>=0x09
AND
TCB[BOOT_LOADER]>=0x3
AND
B1 – TCB[MICROCODE]>=0xA9
B2 –TCB[MICROCODE]>=0x2F

Minimum firmware versions to mitigate all applicable CVEs below

MilanPI 1.0.0.B
(2023-06-14)

CVE-2022-23820

7.5 (High)

MilanPI 1.0.0.3
(2021-05-21)

N/A

N/A

N/A

CVE-2021-46774

6.6 (Medium)

MilanPI 1.0.0.B
(2023-06-14)

N/A

N/A

N/A

CVE-2023-20533

6.1 (Medium)

MilanPI 1.0.0.5
(2021-08-05)

N/A

N/A

TCB[SNP]>=0x08
AND
TCB[BOOT_LOADER]>=0x3

CVE-2023-20519

6.0 (Medium)

MilanPI 1.0.0.A
(2022-10-28)

N/A

1.53.01
(hex 1.35.01)

TCB[SNP]>=0x09

CVE-2023-20566

5.3 (Medium)

MilanPI 1.0.0.B
(2023-06-14)

N/A

1.54.04
 (hex 1.36.04)

TCB[SNP]>=0x0B

CVE-2023-20521

3.3 (Low)

MilanPI 1.0.0.7
(2021-11-11)

N/A

N/A

N/A

CVE-2021-46766

2.5 (Low)

Not affected

N/A

N/A

N/A

CVE-2022-23830

1.9 (Low)

MilanPI 1.0.0.A
(2022-10-28)

Milan B1 - 0x0A0011A9
Milan B2 - 0x0A00122F

1.53.01
(hex 1.35.01) 

B1 – TCB[MICROCODE]>=0xA9

B2 –TCB[MICROCODE]>=0x2F

CVE-2023-20526

1.9 (Low)

MilanPI 1.0.0.5
(2021-08-05)

N/A

N/A

N/A

CVE-2021-26345

1.9 (Low)

MilanPI 1.0.0.A
(2022-10-28)

N/A

N/A

N/A

 

4th Gen AMD EPYC™ Processors formerly codenamed "Genoa"

AMD recommends updating to the Platform Initialization (PI) firmware version indicated below. For some CVEs, there may be alternative mitigation options provided as Mitigation Option 2, including microcode and/or other patches.

CPUIDs

Mitigation Option 1

Mitigation Option 2

TCB Values
for
SNP Attestation

0x00A10F11

0x00A10F12

0x00AA0F0

Platform Initialization (PI)
(Requires FW flash)

μcode
(Hot loadable)

SEV FW
(Hot loadable)

TCB[SNP]>=0x0C
AND
B1 – TCB[MICROCODE]>=0x08

Minimum firmware versions to mitigate all listed CVEs

GenoaPI 1.0.0.8
(2023-06-09)

CVE-2022-23820

7.5 (High)

Not affected

N/A

N/A

N/A

CVE-2021-46774

6.6 (Medium)

GenoaPI 1.0.0.8
(2023-06-09)

N/A

N/A

N/A

CVE-2023-20533

6.1 (Medium)

Not affected

N/A

N/A

N/A

CVE-2023-20519

6.0 (Medium)

GenoaPI 1.0.0.3
(2022-11-18)

N/A

1.53.01
(hex 1.35.01)

TCB[SNP]>=0x09

CVE-2023-20566

5.3 (Medium)

GenoaPI 1.0.0.7
 (2023-04-18)

N/A

1.55.02
(hex 1.37.02)

TCB[SNP]>=0x0C

CVE-2023-20521

3.3 (Low)

Not affected

N/A

N/A

N/A

CVE-2021-46766

2.5 (Low)

GenoaPI 1.0.0.4
(2022-12-27)

N/A

N/A

N/A

CVE-2023-20526

1.9 (Low)

Not affected

N/A

N/A

N/A

CVE-2022-23830

1.9 (Low)

GenoaPI 1.0.0.1
(2022-08-29)


Genoa B1 – 0x0A101108

1.53.01
(hex 1.35.01)

B1 – TCB[MICROCODE]>=0x08

CVE-2021-26345

1.9 (Low)

GenoaPI 1.0.0.0
 (2022-08-04)

N/A

N/A

N/A

 

Acknowledgement

AMD thanks the following for reporting these issues and engaging in coordinated vulnerability disclosure:
Reported by AMI: CVE-2022-23820
Reported by Benjamin Serebrin (formerly of Amazon Web Services): CVE-2022-23830
Internally found: CVE-2023-20533, CVE-2021-46774, CVE-2023-20519, CVE-2023-20566, CVE-2023-20521, CVE-2021-46766, CVE-2023-20526, CVE-2021-26345  

Revisions  

Revision Date  

Description 

11-14-2023

Initial publication

DISCLAIMER

The information contained herein is for informational purposes only and is subject to change without notice. While every precaution has been taken in the preparation of this document, it may contain technical inaccuracies, omissions and typographical errors, and AMD is under no obligation to update or otherwise correct this information. Advanced Micro Devices, Inc. makes no representations or warranties with respect to the accuracy or completeness of the contents of this document, and assumes no liability of any kind, including the implied warranties of noninfringement, merchantability or fitness for particular purposes, with respect to the operation or use of AMD hardware, software or other products described herein. Any computer system has risks of security vulnerabilities that cannot be completely prevented or mitigated. No license, including implied or arising by estoppel, to any intellectual property rights is granted by this document. Terms and limitations applicable to the purchase or use of AMD’s products are as set forth in a signed agreement between the parties or in AMD's Standard Terms and Conditions of Sale.

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