# CVE-2021-38578: Integer overflow in EDK II

> An integer underflow in EDK II SmmEntryPoint allows attackers to bypass buffer checks, potentially leading to code execution or privilege escalation.

- **Severity:** High 7.4 (`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Mar 2022
- **Updated:** 3 Nov 2025
- **Also known as:** DEBIAN-CVE-2021-38578, GHSA-grqq-3jqg-g95p, OESA-2022-2122, UBUNTU-CVE-2021-38578, openSUSE-SU-2024:12542-1

## What is CVE-2021-38578?

CVE-2021-38578 is a high-severity vulnerability in TianoCore EDK II, published on 3 Mar 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Existing CommBuffer checks in SmmEntryPoint will not catch underflow when computing BufferSize.

Weakness: CWE-787 (Out-of-bounds Write), CWE-124 (Buffer Underwrite)

## Which versions are affected by CVE-2021-38578?

It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ovmf` | openSUSE:Tumbleweed | All versions | 202211-1.1 |

Products: Insyde Kernel, Tianocore Edk2.

## How do I fix CVE-2021-38578?

Apply the vendor's patch.

## Is CVE-2021-38578 being exploited?

There is no known exploitation of CVE-2021-38578 in the wild and no public exploit code.

## Other vulnerabilities in TianoCore EDK II

- [CVE-2022-36337](https://insights.sbomify.com/CVE-2022-36337/): Memory corruption in n/a (high 8.2)
- [CVE-2022-29275](https://insights.sbomify.com/CVE-2022-29275/): Privilege escalation in n/a (high 8.2)
- [CVE-2022-29276](https://insights.sbomify.com/CVE-2022-29276/): Memory corruption in n/a (high 8.2)
- [CVE-2022-29278](https://insights.sbomify.com/CVE-2022-29278/): Memory corruption in n/a (high 8.2)
- [CVE-2022-29279](https://insights.sbomify.com/CVE-2022-29279/): Memory corruption in n/a (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-38578 and fix it if it is affected.

What it is: CVE-2021-38578 is a high-severity vulnerability in TianoCore EDK II, published on 3 Mar 2022. 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-2021-38578 in the wild and no public exploit code.

Affected product: TianoCore EDK II. 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-2021-38578/ (Markdown: https://insights.sbomify.com/CVE-2021-38578/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-38578
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-38578
- OSV: https://osv.dev/vulnerability/CVE-2021-38578

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-38578/
Summaries are generated and may contain mistakes; the official description above is the record.