# CVE-2021-27421: NXP MCUXpresso SDK Integer Overflow or Wraparound

> An integer overflow in the SDK_Malloc function allows out-of-bounds memory access, potentially causing a segmentation fault and denial of service.

- **Severity:** High 7.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 May 2022
- **Updated:** 16 Apr 2025
- **Also known as:** GHSA-78hf-2qv8-j9h7

## What is CVE-2021-27421?

CVE-2021-27421 is a high-severity vulnerability in NXP MCUXpresso SDK, published on 3 May 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

NXP MCUXpresso SDK versions prior to 2.8.2 are vulnerable to integer overflow in SDK_Malloc function, which could allow to access memory locations outside the bounds of a specified array, leading to unexpected behavior such segmentation fault when assigning a particular block of memory from the heap via malloc.

Weakness: CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2021-27421?

It affects 1 product.


Products: Nxp Mcuxpresso Software Development Kit.

## How do I fix CVE-2021-27421?

No fix has been published for CVE-2021-27421 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-27421 being exploited?

There is no known exploitation of CVE-2021-27421 in the wild and no public exploit code.

## Other vulnerabilities in NXP MCUXpresso SDK

- [CVE-2019-17519](https://insights.sbomify.com/CVE-2019-17519/): Memory corruption in n/a (high 8.8)
- [CVE-2021-38258](https://insights.sbomify.com/CVE-2021-38258/): Memory corruption in n/a (high 7.8)
- [CVE-2021-38260](https://insights.sbomify.com/CVE-2021-38260/): Memory corruption in n/a (high 7.8)
- [CVE-2019-17060](https://insights.sbomify.com/CVE-2019-17060/): Memory corruption in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-27421 and fix it if it is affected.

What it is: CVE-2021-27421 is a high-severity vulnerability in NXP MCUXpresso SDK, published on 3 May 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-27421 in the wild and no public exploit code.

Affected product: NXP MCUXpresso SDK. 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-2021-27421/ (Markdown: https://insights.sbomify.com/CVE-2021-27421/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-27421
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-27421
- OSV: https://osv.dev/vulnerability/CVE-2021-27421

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-27421/
Summaries are generated and may contain mistakes; the official description above is the record.