# CVE-2021-43784: GO-2022-0274 - Namespace restriction bypass in github.com/opencontainers/runc

Source: https://junglewise.ai/threats/cve-2021-43784-overflow-in-netlink-bytemsg-length-field-allows-attacker-to  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2022-07-15  
License: CC BY 4.0 with a link back

CVE-2021-43784 · Severity: low · CVSS 3.1 · Published 2022-07-15

Namespace restriction bypass in github.com/opencontainers/runc

Technologies: [github.com/opencontainers/runc (Go)](https://junglewise.ai/threats/technologies/github-com-opencontainers-runc). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2021-43784 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-43784 being exploited in the wild.

**How severe is CVE-2021-43784?** Low severity, with a CVSS score of 3.1, published 15 July 2022.

**Which products and versions are affected?** github.com/opencontainers/runc (Go) SEMVER:introduced=0,fixed=1.0.3, SEMVER:introduced=1.0.1-0.20211012131345-9c444070ec7b,fixed=1.1.0.

**Is there a fix for CVE-2021-43784?** Yes. github.com/opencontainers/runc (Go): upgrade to 1.0.3, 1.1.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2021-43784?** Check whether you run github.com/opencontainers/runc (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/opencontainers/runc (Go): upgrade to 1.0.3, 1.1.0 or later

  ```sh
  go get github.com/opencontainers/runc@v1.1.0
  ```


## Affected products

- github.com/opencontainers/runc (Go) SEMVER:introduced=0,fixed=1.0.3, SEMVER:introduced=1.0.1-0.20211012131345-9c444070ec7b,fixed=1.1.0

## Identifiers

- CVE-2021-43784
- GHSA-v95c-p5hm-xq8f
- GO-2022-0274

## Related threats

- [opencontainers runc symlink following in rootfs setup](https://junglewise.ai/threats/cve-2026-41579-opencontainers-runc-symlink-following-in-rootfs-setup)
- [runc container escape with malicious config due to /dev/console mount and related races](https://junglewise.ai/threats/cve-2025-52565-runc-container-escape-with-malicious-config-due-to-dev-console)
- [runc container escape and denial of service due to arbitrary write gadgets and procfs write redirects](https://junglewise.ai/threats/cve-2025-52881-runc-container-escape-and-denial-of-service-due-to-arbitrary)
- [GO-2025-4096 - Container escape via "masked path" abuse due to mount race conditions in github.com/opencontainers/runc](https://junglewise.ai/threats/cve-2025-31133-runc-multiple-container-escape-and-isolation-vulnerabilities)
- [Libcontainer is affected by capabilities elevation similar to GHSA-f3fp-gc8g-vw66](https://junglewise.ai/threats/cve-2025-27612-go-2025-3543-withdrawn-libcontainer-is-affected-by-capabilities)