CVE-2023-31355

Severity: medium (CVSS 6.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-08-05 · updated 2026-06-17
Weakness: CWE-119

Description

Improper restriction of write operations in SNP firmware could allow a malicious hypervisor to overwrite a guest's UMC seed potentially allowing reading of memory from a decommissioned guest.

Affected products

AMD Epyc 7203 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7203P Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 72F3 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7303 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7303P Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7313 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7313P Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7343 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7373X Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 73F3 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7413 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7443 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7443P Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7453 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7473X Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 74F3 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7513 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7543 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7543P Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7573X Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 75F3 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7643 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7643P Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7663 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7663P Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7713 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7713P Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7763 Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 7773X Firmware: before milanpi_1.0.0.d — fixed in milanpi_1.0.0.d
AMD Epyc 8024P Firmware: before genoapi_1.0.0.c — fixed in genoapi_1.0.0.c

How to fix

Upgrade to a fixed version: AMD Epyc 7203 Firmware milanpi_1.0.0.d; AMD Epyc 7203P Firmware milanpi_1.0.0.d; AMD Epyc 72F3 Firmware milanpi_1.0.0.d; AMD Epyc 7303 Firmware milanpi_1.0.0.d; AMD Epyc 7303P Firmware milanpi_1.0.0.d; AMD Epyc 7313 Firmware milanpi_1.0.0.d; AMD Epyc 7313P Firmware milanpi_1.0.0.d; AMD Epyc 7343 Firmware milanpi_1.0.0.d; AMD Epyc 7373X Firmware milanpi_1.0.0.d; AMD Epyc 73F3 Firmware milanpi_1.0.0.d; AMD Epyc 7413 Firmware milanpi_1.0.0.d; AMD Epyc 7443 Firmware milanpi_1.0.0.d. Check the vendor advisory for mitigations.

References

https://https://www.amd.com/en/resources/product-security/bulletin/amd-sb-3011.html

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