AMD SEV-SNP Memory Aliasing Vulnerability Advisory CVE-2024-21944

Vulnerability Overview Vulnerability Name: Undermining Integrity Features of SEV-SNP with Memory Aliasing AMD ID: AMD-SB-3015 Potential Impact: Integrity Loss Severity: Medium CVE ID: CVE-2024-21944 CVSS Score: 5.3 (Medium) Description: Incorrect input validation allows an attacker with physical access to a system, via non-compliant DIMM access or control of the BIOS update Root of Trust, to potentially overwrite guest memory, resulting in a loss of guest data integrity. Affected Products Affected Products: - 3rd Gen AMD EPYC™ Processors (formerly codenamed "Milan") - 3rd Gen AMD EPYC™ Processors (formerly codenamed "Milan-X") - 4th Gen AMD EPYC™ Processors (formerly codenamed "Genoa") - 4th Gen AMD EPYC™ Processors (formerly codenamed "Bergamo") - 4th Gen AMD EPYC™ Processors (formerly codenamed "Genoa-X") - 4th Gen AMD EPYC™ Processors (formerly codenamed "Siena") Remediation Mitigations: - Use memory modules with locked SPD and follow physical security best practices. - Agesa™ and SEV FW updates are released to mitigate this issue; please refer to your OEM's BIOS update. - Specific status information is provided for Host OS / Hypervisor and Virtual Machine (Guest) use to confirm mitigation deployment. - Refer to ABI Specification 56860 for details on Guest Attestation and Platform Status commands. - The SEV FW version includes ALIAS_CHECK mitigation reporting. Specific Versions: - 3rd Gen AMD EPYC™ Processors (Milan and Milan-X): - Platform Initialization (PI) Firmware Version: Milan PI 1.0.0.D (2024-07-11) - SEV FW Version: Milan 1.55.22 (hex 1.37.16) SPL = 0x17 (2024-10-01) - 4th Gen AMD EPYC™ Processors (Genoa, Genoa-X, Bergamo, Siena): - Platform Initialization (PI) Firmware Version: Genoa PI 1.0.0.D (2024-08-20) - SEV FW Version: Genoa 1.55.38 (hex 1.37.26) SPL = 0x16 (2024-10-01) Additional Information SEV Table: - CVE-2024-21944: SEV = N, SEV-ES = N, SEV-SNP = Y Acknowledgments: - We thank the following researchers for reporting this issue and participating in the coordinated vulnerability disclosure: Jesse De Meulemeester (COSIC, KU Leuven), Luca Wilke (University of Lübeck), David Oswald (University of Birmingham), Thomas Eisenbarth (University of Lübeck), Ingrid Verbauwhede (COSIC, KU Leuven), Jo Van Bulck (Distrinet, KU Leuven) Revision History: - 2024-12-10: Initial Release Disclaimer This document is provided for informational purposes only. AMD makes no representations or warranties regarding the accuracy or completeness of the content. All third-party content is provided "as is," and AMD assumes no responsibility for any third-party content. Use of third-party content is at your own risk, and AMD is not liable for any damages arising therefrom. © 2024 Advanced Micro Devices, Inc. All rights reserved.

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AMD SEV-SNP Memory Aliasing Vulnerability Advisory CVE-2024-21944