{"cve":"CVE-2021-23384","nvd":{"published":"2021-05-17T18:15:07.733","modified":"2026-06-17T03:38:39.843","status":"Modified","description":"The package koa-remove-trailing-slashes before 2.0.2 are vulnerable to Open Redirect via the use of trailing double slashes in the URL when accessing the vulnerable endpoint (such as https://example.com//attacker.example/). The vulnerable code is in index.js::removeTrailingSlashes(), as the web server uses relative URLs instead of absolute URLs.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","score":5.4},"cwes":["CWE-601"],"references":["https://github.com/vgno/koa-remove-trailing-slashes/blame/6a01ba8fd019bd3ece44879c553037ad96ba7d47/index.js%23L31","https://snyk.io/vuln/SNYK-JS-KOAREMOVETRAILINGSLASHES-1085708","https://github.com/vgno/koa-remove-trailing-slashes/blame/6a01ba8fd019bd3ece44879c553037ad96ba7d47/index.js%23L31","https://snyk.io/vuln/SNYK-JS-KOAREMOVETRAILINGSLASHES-1085708"],"products":["koa-remove-trailing-slashes_project:koa-remove-trailing-slashes"],"source":"nvd","synced_at":"2026-10-19T21:18:09.669877188+00:00"},"epss":{"cve":"CVE-2021-23384","score":0.00835,"percentile":0.57709,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-r773-pmw3-f4mr","url":"https://osv.dev/vulnerability/GHSA-r773-pmw3-f4mr","summary":"Open Redirect in koa-remove-trailing-slashes","modified":"2026-03-13T21:56:59.448210Z","packages":[{"ecosystem":"npm","name":"koa-remove-trailing-slashes","purl":"pkg:npm/koa-remove-trailing-slashes","ranges":["<2.0.2"],"fixed":["2.0.2"]}]}],"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."]}