# CVE-2023-31100: Missing authorization in SecureCore™ Technology™ 4

> Attackers can modify SPI flash via improper access control in the SMI handler, potentially leading to code execution or privilege escalation.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/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:** 14 Nov 2023
- **Updated:** 28 Jul 2025
- **Also known as:** GHSA-h3cr-gxpm-fxxc

## What is CVE-2023-31100?

CVE-2023-31100 is a high-severity missing authorization vulnerability in Phoenix SecureCore™ Technology™ 4, published on 14 Nov 2023. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Improper Access Control in SMI handler vulnerability in Phoenix SecureCore™ Technology™ 4 allows SPI flash modification.
This issue affects SecureCore™ Technology™ 4:

  *  from 4.3.0.0 before 4.3.0.203
  *  

from 

4.3.1.0 before 4.3.1.163
  *  

from 

4.4.0.0 before 4.4.0.217
  *  

from 

4.5.0.0 before 4.5.0.138

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2023-31100?

It affects 1 product.


Products: Phoenixtech Securecore Technology.

## How do I fix CVE-2023-31100?

No fix has been published for CVE-2023-31100 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-31100 being exploited?

There is no known exploitation of CVE-2023-31100 in the wild and no public exploit code.

## Other vulnerabilities in Phoenix SecureCore™ Technology™ 4

- [CVE-2023-5058](https://insights.sbomify.com/CVE-2023-5058/): Other in SecureCore™ Technology™ 4 (high 7.8)
- [CVE-2024-0762](https://insights.sbomify.com/CVE-2024-0762/): Potential buffer overflow when handling UEFI variables (high 7.5)
- [CVE-2024-1598](https://insights.sbomify.com/CVE-2024-1598/): Potential buffer overflow when handling UEFI variables (high 7.5)
- [CVE-2024-29979](https://insights.sbomify.com/CVE-2024-29979/): Unsafe Handling of Phoenix UEFI Variables (medium 4.6)
- [CVE-2024-29980](https://insights.sbomify.com/CVE-2024-29980/): Unsafe Handling of IHV UEFI Variables (medium 4.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-31100 and fix it if it is affected.

What it is: CVE-2023-31100 is a high-severity missing authorization vulnerability in Phoenix SecureCore™ Technology™ 4, published on 14 Nov 2023. 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-2023-31100 in the wild and no public exploit code.

Affected product: Phoenix SecureCore™ Technology™ 4. 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-2023-31100/ (Markdown: https://insights.sbomify.com/CVE-2023-31100/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-31100
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-31100
- OSV: https://osv.dev/vulnerability/CVE-2023-31100

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-31100/
Summaries are generated and may contain mistakes; the official description above is the record.