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NVD / CVE Program· CNA Insyde

CVE-2025-4275: SecureFlashDxe: Incorrect UEFI variable attributes check allows usage of invalid certificate

Noroxi assessment

Priority: Monitor (action score 31/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.48% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Insyde Software InsydeH2O 05.2A.16, 05.39.16, 05.47.16.

Low priority for now. Upgrade to Insyde Software InsydeH2O 05.2A.16, 05.39.16, 05.47.16 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

A vulnerability in the digital signature verification process does not properly validate variable attributes which allows an attacker to bypass signature verification by creating a non-authenticated NVRAM variable. An attacker may to execute arbitrary signed UEFI code and bypass Secure Boot.

HighCVSS 7.8 · v3.1—Proof of concept Fix available
Published
Jun 10, 2025
Updated
Jun 17, 2026
EPSS
0.4% · 41th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Insyde
7.8
NVD has not scored this yet; the score shown is the CNA’s.

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-2025-4275

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.

—

Versions reported by the vendor

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

  • Insyde Software InsydeH2O

    • Kernel 5.2 and later · before 05.2A.16affected · Tag
    • Kernel 5.3 and later · before 05.39.16affected · Tag
    • Kernel 5.4 and later · before 05.47.16affected · Tag
    • Kernel 5.5 and later · before 05.55.16affected · Tag
    • Kernel 5.6 and later · before 05.62.16affected · Tag
    • Kernel 5.7 and later · before 05.71.16affected · Tag

Same product

insyde software: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-12855H19WMIHandlerSmm: unvalidated memory boundary could result in arbitrary code execution.
    32Monitor
  • CVE-2026-6485UEFI BIOS embedded Shell can be used to bypass Secure Boot
    32Monitor
  • CVE-2021-38489HDD Password Stored In Plaintext
    32Monitor

Published before and after this one in the same product

  • Later →CVE-2025-4421Jul 29, 2025 · EfiSmiServices: gEfiSmmCpuProtocol, SMM memory corruption vulnerabilities in SMM module
    32Monitor
  • Later →CVE-2025-4422Jul 29, 2025 · EfiSmiServices : EfiPcdProtocol, SMM memory corruption vulnerabilities in SMM module
    32Monitor
  • Later →CVE-2025-4423Jul 29, 2025 · SetupAutomationSmm:Vulnerability in the SMM module allow attacker to write arbitrary code and lead to memory corruption
    32Monitor

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
Insyde Software InsydeH2O05.2A.16Vendor (CNA)
Insyde Software InsydeH2O05.39.16Vendor (CNA)
Insyde Software InsydeH2O05.47.16Vendor (CNA)
Insyde Software InsydeH2O05.55.16Vendor (CNA)
Insyde Software InsydeH2O05.62.16Vendor (CNA)
Insyde Software InsydeH2O05.71.16Vendor (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 ×3

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:422025-06-10
Proof-of-concept repository on GitHubstars:02026-01-12
Proof-of-concept repository on GitHubstars:02026-10-22

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-1 d
  2. Published
  3. TodayNov 8, 2026+516 d

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.

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

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted

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

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

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

Attack context

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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

References

Show all references (1 more)

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

All records