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NVD / CVE Program· CNA AMD

CVE-2021-46756: Insufficient validation of inputs in SVC_MAP_USER_STACK in the ASP (AMD Secure Processor) bootloader may allow an attacker with a malicious

Noroxi assessment

Priority: Monitor (action score 36/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.64% (FIRST EPSS); higher than 51.1% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

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

Insufficient validation of inputs in SVC_MAP_USER_STACK in the ASP (AMD Secure Processor) bootloader may allow an attacker with a malicious Uapp or ABL to send malformed or invalid syscall to the bootloader resulting in a potential denial of service and loss of integrity.

CriticalCVSS 9.1 · v3.1—No exploit No fix recorded
Published
May 9, 2023
Updated
Jun 17, 2026
EPSS
0.6% · 51th percentile

Report tools

JSON

Action score

36

Monitor

Low priority for now.

CVSS
36 / 40 · 9.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

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

Follow CVE-2021-46756

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 72f3 firmware
amdepyc 72f3
amdepyc 7313 firmware
amdepyc 7313
amdepyc 7313p firmware
amdepyc 7313p
amdepyc 7343 firmware
amdepyc 7343
amdepyc 7373x firmware
amdepyc 7373x
amdepyc 73f3 firmware
amdepyc 73f3

and 114 more

Affected versions

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

  • amd epyc 7232p firmwareromepi_1.0.0.e
  • amd epyc 7251 firmwarenaplespi_1.0.0.j
  • amd epyc 7252 firmwareromepi_1.0.0.e
  • amd epyc 7261 firmwarenaplespi_1.0.0.j
  • amd epyc 7262 firmwareromepi_1.0.0.e
  • amd epyc 7272 firmwareromepi_1.0.0.e
  • amd epyc 7281 firmwarenaplespi_1.0.0.j
  • amd epyc 7282 firmwareromepi_1.0.0.e
  • amd epyc 72f3 firmwaremilanpi_1.0.0.9
  • amd epyc 7301 firmwarenaplespi_1.0.0.j
  • amd epyc 7302 firmwareromepi_1.0.0.e
  • amd epyc 7302p firmwareromepi_1.0.0.e
  • amd epyc 7313 firmwaremilanpi_1.0.0.9
  • amd epyc 7313p firmwaremilanpi_1.0.0.9
  • amd epyc 7343 firmwaremilanpi_1.0.0.9
  • amd epyc 7351 firmwarenaplespi_1.0.0.j
  • amd epyc 7351p firmwarenaplespi_1.0.0.j
  • amd epyc 7352 firmwareromepi_1.0.0.e
  • amd epyc 7371 firmwarenaplespi_1.0.0.j
  • amd epyc 7373x firmwaremilanpi_1.0.0.9

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 1st Gen AMD EPYC™ Processors

    • variousaffected

  • AMD 2nd Gen AMD EPYC™ Processors

    • variousaffected

  • AMD 2nd Gen AMD Ryzen™ Threadripper™ Processors “Colfax”

    • variousaffected

  • AMD 3rd Gen AMD EPYC™ Processors

    • variousaffected

  • AMD 3rd Gen AMD Ryzen™ Threadripper™ Processors “Castle Peak” HEDT

    • variousaffected

  • AMD AMD Ryzen™ 5000 Series Desktop Processors “Vermeer” AM4

    • variousaffected

  • AMD Athlon™ 3000 Series Mobile Processors with Radeon™ Graphics “Pollock”

    • variousaffected

  • AMD Athlon™ 3000 Series Mobile Processors with Radeon™ Graphics “Dali”/”Dali” ULP

    • variousaffected

  • AMD Ryzen™ 2000 Series Desktop Processors “Pinnacle Ridge”

    • variousaffected

  • AMD Ryzen™ 2000 series Desktop Processors “Raven Ridge” AM4

    • variousaffected

  • AMD Ryzen™ 2000 Series Mobile Processors “Raven Ridge” FP5

    • variousaffected

  • AMD Ryzen™ 3000 Series Desktop Processors “Matisse” AM4

    • variousaffected

Same product

amd: all records

Other highest-scoring records for the same primary product.

  • CVE-2023-20520Improper access control settings in ASP Bootloader may allow an attacker to corrupt the return address causing a stack-based buffer overrun
    39Monitor
  • CVE-2021-26379Insufficient input validation of mailbox data in the SMU may allow an attacker to coerce the SMU to corrupt SMRAM, potentially leading to a
    39Monitor
  • CVE-2021-46762Insufficient input validation in the SMU may allow an attacker to corrupt SMU SRAM potentially leading to a loss of integrity or denial of s
    36Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2021-46775May 9, 2023 · Improper input validation in ABL may enable an attacker with physical access, to perform arbitrary memory overwrites, potentially leading to
    27Monitor
  • ← EarlierCVE-2022-23818May 9, 2023 · Insufficient input validation on the model specific register: VM_HSAVE_PA may potentially lead to loss of SEV-SNP guest memory integrity.
    30Monitor
  • ← EarlierCVE-2023-20524May 9, 2023 · An attacker with a compromised ASP could possibly send malformed commands to an ASP on another CPU, resulting in an out of bounds write, pot
    30Monitor

Remediation

Which version to upgrade to

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

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

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.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

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.

No nightly-computed relations.

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

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-20 · Improper Input Validation

CVSS vector

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

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.

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (1 more)

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

All records