# CVE-2021-42374: Information disclosure in busybox

> Attackers can cause information leaks and denial of service in BusyBox by providing crafted LZMA-compressed input to the unlzma applet.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/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:** Yes
- **Published:** 15 Nov 2021
- **Updated:** 3 Nov 2025
- **Also known as:** ALPINE-CVE-2021-42374, AZL-41054, AZL-6343, DEBIAN-CVE-2021-42374, GHSA-6f92-r9cq-v6cq, OESA-2021-1441, UBUNTU-CVE-2021-42374

## What is CVE-2021-42374?

CVE-2021-42374 is a medium-severity vulnerability in Fedoraproject Fedora, published on 15 Nov 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An out-of-bounds heap read in Busybox's unlzma applet leads to information leak and denial of service when crafted LZMA-compressed input is decompressed. This can be triggered by any applet/format that

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2021-42374?

It affects 12 products.


Products: Busybox Busybox, Fedoraproject Fedora, Netapp Cloud Backup, Netapp H300e Firmware, Netapp H300s Firmware, Netapp H410s Firmware, Netapp H500e Firmware, Netapp H500s Firmware, Netapp H700e Firmware, Netapp H700s Firmware, Netapp Hci Management Node, Netapp Solidfire.

## How do I fix CVE-2021-42374?

Apply the vendor's patch.

## Is CVE-2021-42374 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-42374 exists.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2022-48174](https://insights.sbomify.com/CVE-2022-48174/): Memory corruption in n/a (critical 9.8)
- [CVE-2021-42377](https://insights.sbomify.com/CVE-2021-42377/): Memory corruption in busybox (critical 9.8)
- [CVE-2016-2148](https://insights.sbomify.com/CVE-2016-2148/): Memory corruption in n/a (critical 9.8)
- [CVE-2022-28391](https://insights.sbomify.com/CVE-2022-28391/): Command injection in n/a (high 8.8)
- [CVE-2017-16544](https://insights.sbomify.com/CVE-2017-16544/): Code injection in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42374 and fix it if it is affected.

What it is: CVE-2021-42374 is a medium-severity vulnerability in Fedoraproject Fedora, published on 15 Nov 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-42374 exists.

Affected product: Fedoraproject Fedora. 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-2021-42374/ (Markdown: https://insights.sbomify.com/CVE-2021-42374/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42374
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42374
- OSV: https://osv.dev/vulnerability/CVE-2021-42374

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-42374/
Summaries are generated and may contain mistakes; the official description above is the record.