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CVE-2023-31355· NVD / CVE Program· CNA AMD

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

Noroxi assessment

Priority: Monitor (action score 24/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.44% (FIRST EPSS).
  • Someone with local access to the system can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: 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.

Low priority for now. Upgrade to 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 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 6.0 · v3.1—Proof of concept Fix available
Published
Aug 5, 2024
Updated
Jun 17, 2026
EPSS
0.4% · 37th percentile

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
24 / 40 · 6.0 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
6.0
CNA · AMD
6.0
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2023-31355

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
amdepyc 7203 firmware
amdepyc 7203
amdepyc 7203p firmware
amdepyc 7203p
amdepyc 72f3 firmware
amdepyc 72f3
amdepyc 7303 firmware
amdepyc 7303
amdepyc 7303p firmware
amdepyc 7303p
amdepyc 7313 firmware
amdepyc 7313

and 160 more

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • amd epyc 7203 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7203p firmwarebefore milanpi_1.0.0.d
  • amd epyc 72f3 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7303 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7303p firmwarebefore milanpi_1.0.0.d
  • amd epyc 7313 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7313p firmwarebefore milanpi_1.0.0.d
  • amd epyc 7343 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7373x firmwarebefore milanpi_1.0.0.d
  • amd epyc 73f3 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7413 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7443 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7443p firmwarebefore milanpi_1.0.0.d
  • amd epyc 7453 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7473x firmwarebefore milanpi_1.0.0.d
  • amd epyc 74f3 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7513 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7543 firmwarebefore milanpi_1.0.0.d
  • amd epyc 7543p firmwarebefore milanpi_1.0.0.d
  • amd epyc 7573x firmwarebefore milanpi_1.0.0.d

Versions reported by the vendor

Affected version ranges reported by the assigning authority (AMD). Independent of NVD's CPE analysis and usually ahead of it.

  • AMD 3rd Gen AMD EPYC™ Processors

    • various and later · before MilanPI 1.0.0.Daffected · Platform Initialization

  • AMD 4th Gen AMD EPYC™ Processors

    • various and later · before GenoaPI 1.0.0.Caffected · Platform Initialization

  • AMD AMD EPYC™ Embedded 7003

    • various and later · before EmbMilanPI-SP3 1.0.0.9affected · Platform Initialization

  • AMD AMD EPYC™ Embedded 9003

    • various and later · before EmbGenoaPI-SP5 1.0.0.7affected · Platform Initialization

Same product

amd: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-26344An out of bounds memory write when processing the AMD PSP1 Configuration Block (APCB) could allow an attacker with access the ability to mod
    32Monitor
  • CVE-2024-21980Improper restriction of write operations in SNP firmware could allow a malicious hypervisor to potentially overwrite a guest's memory or UMC
    31Monitor
  • CVE-2024-21978Improper input validation in SEV-SNP could allow a malicious hypervisor to read or overwrite guest memory potentially leading to data leakag
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
AMD 3rd Gen AMD EPYC™ ProcessorsMilanPI 1.0.0.DVendor (CNA)
AMD 4th Gen AMD EPYC™ ProcessorsGenoaPI 1.0.0.CVendor (CNA)
AMD AMD EPYC™ Embedded 7003EmbMilanPI-SP3 1.0.0.9Vendor (CNA)
AMD AMD EPYC™ Embedded 9003EmbGenoaPI-SP5 1.0.0.7Vendor (CNA)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:82023-12-08

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-242 d
  2. Published
  3. TodayOct 23, 2026+809 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2024-219800 days apartImproper restriction of write operations in SNP firmware could allow a malicious hypervisor to potentially overwrite a guest's memory or UMC
    31Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • Administrator privileges are required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Local
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
Changed
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records