{"id":"CVE-2021-22963","aliases":["EUVD-2021-2234","GHSA-p6vg-p826-qp3v"],"status":"published","title":"URL Redirection to Untrusted Site ('Open Redirect') in fastify-static","description":"A redirect vulnerability in the fastify-static module version \u003c 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.","severity":{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-11","score":0.01169,"percentile":0.67804,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-601"],"published":"2021-10-05T20:24:49Z","modified":"2026-10-24T10:30:35Z","fixes":[{"ecosystem":"npm","package":"fastify-static","fixed_in":["4.2.4"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"fastify-static","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.4"}]}]},{"source":"osv","ecosystem":"npm","package":"fastify-static","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"4.2.4"}]}]}],"products":[{"vendor":"fastify","product":"fastify-static"}],"references":[{"url":"https://hackerone.com/reports/1354255","tags":["x_refsource_MISC","x_transferred","Exploit","Issue Tracking","Third Party Advisory","report","web"]},{"url":"https://github.com/fastify/fastify-static/security/advisories/GHSA-p6vg-p826-qp3v","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-22963","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-p6vg-p826-qp3v"},{"url":"https://github.com/fastify/fastify-static","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2021-22963","description":"A redirect vulnerability in the fastify-static module version \u003c 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.","status":"published","published":"2021-10-14T14:50:11Z","modified":"2024-08-03T18:58:26.158Z","cwes":["CWE-601"],"updated_at":"2026-11-02T14:32:57.701381Z"}],"euvd":[{"id":"EUVD-2021-2234","description":"A redirect vulnerability in the fastify-static module version \u003c 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.","status":"published","published":"2021-10-14T14:50:11Z","modified":"2024-08-03T18:58:26Z","updated_at":"2026-11-03T03:25:00.591933Z"}],"ghsa":[{"id":"GHSA-p6vg-p826-qp3v","title":"URL Redirection to Untrusted Site ('Open Redirect') in fastify-static","description":"### 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//google.com/%2e%2e`.\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@4.2.4`\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/1354255)\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","status":"published","published":"2021-10-05T20:24:49Z","modified":"2023-02-01T05:06:10Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T14:36:37.441118Z"}],"nvd":[{"id":"CVE-2021-22963","description":"A redirect vulnerability in the fastify-static module version \u003c 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.","status":"published","published":"2021-10-14T15:15:08.877Z","modified":"2026-06-17T03:38:07.07Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"},{"version":"2.0","score":5.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T14:06:59.689345Z"}],"osv":[{"id":"CVE-2021-22963","description":"A redirect vulnerability in the fastify-static module version \u003c 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.","status":"published","published":"2021-10-14T15:15:08.877Z","modified":"2026-10-24T10:30:35.176880683Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:44:18.367807Z"},{"id":"GHSA-p6vg-p826-qp3v","title":"URL Redirection to Untrusted Site ('Open Redirect') in fastify-static","description":"### 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//google.com/%2e%2e`.\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@4.2.4`\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/1354255)\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","status":"published","published":"2021-10-05T20:24:49Z","modified":"2023-11-08T04:05:02.185397Z","cvss":[{"version":"3.1","score":6.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-601"],"updated_at":"2026-11-02T15:46:52.891208Z"}]}}