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Fencer Vulns
medium 6.0

CVE-2023-31355 json

Improper restriction of write operations in SNP firmware could allow a malicious hypervisor to overwrite a guest's UMC seed potentially all…

published 2024-08-05 2 y ago modified 2026-06-17 4 mo ago also EUVD-2023-35666

cvss
6.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

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.

Patch / fix

  • AMD 3rd Gen AMD EPYC™ Processors MilanPI 1.0.0.D
  • AMD 4th Gen AMD EPYC™ Processors GenoaPI 1.0.0.C
  • AMD AMD EPYC™ Embedded 7003 EmbMilanPI-SP3 1.0.0.9
  • AMD AMD EPYC™ Embedded 9003 EmbGenoaPI-SP5 1.0.0.7

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-31355 updated cvss 6.0

linux-firmware: hw:amd: Improper Restriction of Write Operations in SNP Firmware

  • Red Hat Enterprise Linux 7 linux-firmware, iwl100-firmware, iwl105-firmware, iwl135-firmware, iwl1000-firmware, iwl2000-firmware, +12 more Red Hat Enterprise Linux 8 linux-firmware, iwl100-firmware, iwl105-firmware, iwl135-firmware, iwl1000-firmware, iwl2000-firmware, +15 more Red Hat Enterprise Linux 9 linux-firmware, iwl100-firmware, iwl105-firmware, iwl135-firmware, iwl1000-firmware, iwl2000-firmware, +11 more Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.0 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
NVD 3.1 6.0 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

Affected products

  • AMD 3rd Gen AMD EPYC™ Processors
  • AMD 4th Gen AMD EPYC™ Processors
  • AMD AMD EPYC™ Embedded 7003
  • AMD AMD EPYC™ Embedded 9003

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
  • CWE-787 Out-of-bounds Write

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.