{"id":"CVE-2021-22964","aliases":["GHSA-pgh6-m65r-2rhq"],"url":"https://o3.security/vulnerability/CVE-2021-22964","summary":"DOS and Open Redirect with user input","details":"### Impact\n\nA redirect vulnerability in the `fastify-static` module 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`.\n\nA DOS vulnerability is possible if the URL contains invalid characters `curl --path-as-is \"http://localhost:3000//^/..\"`\n\nThe issue shows up on all the `fastify-static` applications that set `redirect: true` option. By default, it is `false`.\n\n### Patches\nThe issue has been patched in `fastify-static@4.4.1`\n\n### Workarounds\nIf updating is not an option, you can sanitize the input URLs using the [`rewriteUrl`](https://www.fastify.io/docs/latest/Server/#rewriteurl) server option.\n\n### References\n\n+ Bug founder: drstrnegth\n+ [hackerone Report](https://hackerone.com/reports/1361804)\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [fastify-static](https://github.com/fastify/fastify-static)\n* Contact the [security team](https://github.com/fastify/fastify/blob/main/SECURITY.md#the-fastify-security-team)\n","published":"2021-10-14T15:15:08.933Z","modified":"2026-07-09T00:06:05.686755Z","cvss":{"score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"npm","name":"fastify-static","fixedVersion":"4.4.1"}],"fix":{"url":"https://github.com/fastify/fastify-static/commit/c31f17d107cb19a0e96733c80a9abf16c56166d4","label":"fastify/fastify-static@c31f17d"},"references":[{"type":"FIX","url":"https://hackerone.com/reports/1361804"},{"type":"WEB","url":"https://github.com/fastify/fastify-static/security/advisories/GHSA-pgh6-m65r-2rhq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-22964"},{"type":"WEB","url":"https://github.com/fastify/fastify-static/commit/c31f17d107cb19a0e96733c80a9abf16c56166d4"},{"type":"PACKAGE","url":"https://github.com/fastify/fastify-static"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T00:06:05.686755Z"}}