# CVE-2021-46242: Use after free in n/a

> A heap-use-after-free vulnerability in the HDF5 library allows attackers to execute arbitrary code or cause a denial of service.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 21 Jan 2022
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2021-46242, ECHO-8d02-7a22-e43e, GHSA-x9pw-hh7v-wjpf, ROOT-OS-DEBIAN-12-CVE-2021-46242, UBUNTU-CVE-2021-46242

## What is CVE-2021-46242?

CVE-2021-46242 is a high-severity use after free vulnerability in Hdfgroup Hdf5, published on 21 Jan 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

HDF5 v1.13.1-1 was discovered to contain a heap-use-after free via the component H5AC_unpin_entry.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2021-46242?

It affects 1 product.


Products: Hdfgroup Hdf5.

## How do I fix CVE-2021-46242?

Upgrade to a fixed version.

## Is CVE-2021-46242 being exploited?

There is no known exploitation of CVE-2021-46242 in the wild and no public exploit code.

## Other vulnerabilities in Hdfgroup Hdf5

- [CVE-2024-32608](https://insights.sbomify.com/CVE-2024-32608/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-29157](https://insights.sbomify.com/CVE-2024-29157/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-29159](https://insights.sbomify.com/CVE-2024-29159/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-29164](https://insights.sbomify.com/CVE-2024-29164/): Memory corruption in n/a (critical 9.8)
- [CVE-2024-32611](https://insights.sbomify.com/CVE-2024-32611/): Other in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-46242 and fix it if it is affected.

What it is: CVE-2021-46242 is a high-severity use after free vulnerability in Hdfgroup Hdf5, published on 21 Jan 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-46242 in the wild and no public exploit code.

Affected product: Hdfgroup Hdf5. 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-2021-46242/ (Markdown: https://insights.sbomify.com/CVE-2021-46242/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-46242
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-46242
- OSV: https://osv.dev/vulnerability/CVE-2021-46242

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-46242/
Summaries are generated and may contain mistakes; the official description above is the record.