{"cve":"CVE-2021-22964","nvd":{"published":"2021-10-14T15:15:08.933","modified":"2026-06-17T03:38:07.180","status":"Modified","description":"A redirect vulnerability in the `fastify-static` module version >= 4.2.4 and < 4.4.1 allows remote attackers to redirect Mozilla Firefox users to arbitrary websites via a double slash `//` followed by a domain: `http://localhost:3000//a//youtube.com/%2e%2e%2f%2e%2e`.A DOS vulnerability is possible if the URL contains invalid characters `curl --path-as-is \"http://localhost:3000//^/..\"`The issue shows up on all the `fastify-static` applications that set `redirect: true` option. By default, it is `false`.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:H","score":8.8},"cwes":["CWE-601","CWE-400"],"references":["https://hackerone.com/reports/1361804","https://hackerone.com/reports/1361804"],"products":["fastify:fastify-static"],"source":"nvd","synced_at":"2026-10-19T21:24:39.218183596+00:00"},"epss":{"cve":"CVE-2021-22964","score":0.01021,"percentile":0.63438,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-pgh6-m65r-2rhq","url":"https://osv.dev/vulnerability/GHSA-pgh6-m65r-2rhq","summary":"DOS and Open Redirect with user input","modified":"2023-11-08T04:05:02.248197Z","packages":[{"ecosystem":"npm","name":"fastify-static","purl":"pkg:npm/fastify-static","ranges":[">=4.2.4 <4.4.1"],"fixed":["4.4.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}