SEV-SNP Firmware Vulnerabilities
Bulletin ID: AMD-SB-3007
Potential Impact:Data leakage (CVE-2023-31346) and loss of integrity (CVE-2023-31347)
Severity:Refer to the CVE Details section
Summary
This bulletin addresses two SEV firmware vulnerabilities reported by an external researcher. Refer to the CVE Details section below.
CVE Details
Refer to Glossary for explanation of terms
| CVE | Severity | CVE Description |
| CVE-2023-31346 | Medium | Failure to initialize memory in SEV Firmware may allow a privileged attacker to access stale data from other guests. |
| CVE-2023-31347 | Low | Due to a code bug in Secure_TSC, SEV firmware may allow an attacker with high privileges to cause a guest to observe an incorrect TSC when Secure TSC is enabled potentially resulting in a loss of guest integrity. |
Affected Products and Mitigation
AMD is releasing SEV firmware and Platform Initialization (PI) updates to help mitigate these potential vulnerabilities.
3rd Gen AMD EPYC™ Processors formerly codenamed “Milan"
AMD recommends updating to the Platform Initialization (PI) firmware version indicated below.
For both CVEs, there is an alternative mitigation option provided as Mitigation Option 2, including a SEV firmware patch.
| 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] >= 0x14 | |
| Minimum firmware versions to mitigate all listed CVEs | MilanPI 1.0.0.C (2023-12-18) |
||||
| CVE-2023-31346 | Medium | MilanPI 1.0.0.C (2023-12-18) |
N/A | 1.37.10 | TCB[SNP] >= 0x14 |
| CVE-2023-31347 | Low | MilanPI 1.0.0.C (2023-12-18) |
N/A | 1.37.10 | |
4th Gen AMD EPYC™ Processors formerly codenamed "Genoa"
AMD recommends updating to the Platform Initialization (PI) firmware version indicated below.
For both CVEs, there is an alternative mitigation option provided as Mitigation Option 2, including a SEV firmware patch.
| 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] >= 0x12 | |
| Minimum firmware versions to mitigate all listed CVEs | GenoaPI 1.0.0.B (2023-12-15) |
||||
| CVE-2023-31346 | Medium | GenoaPI 1.0.0.B (202312-15) |
N/A | 1.37.1E | TCB[SNP] >= 0x12 |
| CVE-2023-31347 | Low | GenoaPI 1.0.0.B (202312-15) |
N/A | 1.37.1E | |
Acknowledgement
AMD thanks Tom Dohrmann for reporting this issue and engaging in coordinated vulnerability disclosure.
Revisions
Revision Date |
Description |
2024-02-13 |
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.
AMD, the AMD Arrow logo, EPYC and combinations thereof are trademarks of Advanced Micro Devices, Inc. CVE and the CVE logo are registered trademarks of The MITRE Corporation. Other product names used in this publication are for identification purposes only and may be trademarks of their respective companies.
Third party content may be licensed to you directly by the third party that owns the content and is not licensed to you by AMD. ALL LINKED THIRD-PARTY CONTENT IS PROVIDED ‘AS IS’ WITHOUT A WARRANTY OF ANY KIND. USE OF SUCH THIRD-PARTY CONTENT IS DONE AT YOUR SOLE DISCRETION AND UNDER NO CIRCUMSTANCES WILL AMD BE LIABLE TO YOU FOR ANY THIRD-PARTY CONTENT. YOU ASSUME ALL RISK AND ARE SOLELY RESPONSIBILITY FOR ANY DAMAGES THAT MAY ARISE FROM YOUR USE OF THIRD-PARTY CONTENT.
© 2024 Advanced Micro Devices, Inc. All rights reserved.