# CVE-2021-42377: Memory corruption in busybox

> An attacker can cause denial of service or execute code by exploiting a memory corruption flaw in BusyBox's hush shell when processing specific commands.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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:** Not needed
- **Fix available:** Yes
- **Published:** 15 Nov 2021
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2021-42377, GHSA-phvg-gc27-gjwp

## What is CVE-2021-42377?

CVE-2021-42377 is a critical memory corruption vulnerability in Fedoraproject Fedora, published on 15 Nov 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An attacker-controlled pointer free in Busybox's hush applet leads to denial of service and possible code execution when processing a crafted shell command, due to the shell mishandling the &&& string. This may be used for remote code execution under rare conditions of filtered command input.

Weakness: CWE-763 (Release of Invalid Pointer or Reference), CWE-590 (Free of Memory not on the Heap)

## Which versions are affected by CVE-2021-42377?

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-2021-42377?

Apply the vendor's patch.

## Is CVE-2021-42377 being exploited?

There is no known exploitation of CVE-2021-42377 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2022-48174](https://insights.sbomify.com/CVE-2022-48174/): Memory corruption in n/a (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)
- [CVE-2018-1000517](https://insights.sbomify.com/CVE-2018-1000517/): Memory corruption in n/a (high 8.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42377 and fix it if it is affected.

What it is: CVE-2021-42377 is a critical memory corruption vulnerability in Fedoraproject Fedora, published on 15 Nov 2021. 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-2021-42377 in the wild and no public exploit code.

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-2021-42377/ (Markdown: https://insights.sbomify.com/CVE-2021-42377/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42377
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42377
- OSV: https://osv.dev/vulnerability/CVE-2021-42377

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-42377/
Summaries are generated and may contain mistakes; the official description above is the record.