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

> Attackers can bypass Secure Boot and execute arbitrary signed UEFI code by exploiting improper validation of UEFI variable attributes in InsydeH2O firmware.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Jun 2025
- **Updated:** 14 Aug 2025
- **Also known as:** GHSA-v9r5-7mg9-fwrr

## What is CVE-2025-4275?

CVE-2025-4275 is a high-severity vulnerability in InsydeH2O, published on 11 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

## Which versions are affected by CVE-2025-4275?


## How do I fix CVE-2025-4275?

No fix has been published for CVE-2025-4275 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-4275 being exploited?

There is no known exploitation of CVE-2025-4275 in the wild and no public exploit code.

Public exploit code:

- Binaries, drivers, PoCs and other stuff on Hydroph0bia vulnerability (CVE-2025-4275) (github_poc): https://github.com/NikolajSchlej/Hydroph0bia
- Analysis and exploitation of CVE-2025-4275 (Hydr0ph0bia), a Secure Boot trust-chain weakness where firmware variables are used to introduce attacker-controlled certificates trusted by subsequent boot components. (github_poc): https://github.com/TheMalwareGuardian/CVE-2025-4275
- Read-only defender scanner for CVE-2025-4275 (Hydroph0bia) on Insyde H2O firmware. Companion to Insyde SA-2025002 / CERT/CC VU#211341. (github_poc): https://github.com/Dorlander/hydrophobia-scanner

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-4275 and fix it if it is affected.

What it is: CVE-2025-4275 is a high-severity vulnerability in InsydeH2O, published on 11 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-4275 in the wild and no public exploit code.

Affected product: InsydeH2O. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-4275/ (Markdown: https://insights.sbomify.com/CVE-2025-4275/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-4275
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-4275
- OSV: https://osv.dev/vulnerability/CVE-2025-4275

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-4275/
Summaries are generated and may contain mistakes; the official description above is the record.