{"id":"GHSA-p6j9-7xhc-rhwp","summary":"URIjs Hostname spoofing via backslashes in URL","details":"### Impact\nIf using affected versions to determine a URL's hostname, the hostname can be spoofed by using a backslash (`\\`) character as part of the scheme delimiter, e.g. `scheme:/\\hostname`. If the hostname is used in security decisions, the decision may be incorrect.\n\nDepending on library usage and attacker intent, impacts may include allow/block list bypasses, SSRF attacks, open redirects, or other undesired behavior.\n\nExample URL: `https:/\\expected-example.com/path`\nEscaped string: `https:/\\\\expected-example.com/path` (JavaScript strings must escape backslash)\n\nAffected versions incorrectly return no hostname. Patched versions correctly return `expected-example.com`. Patched versions match the behavior of other parsers which implement the [WHATWG URL specification](https://url.spec.whatwg.org/), including web browsers and [Node's built-in URL class](https://nodejs.org/api/url.html).\n\n### Patches\nVersion 1.19.6 is patched against all known payload variants.\n\n### References\nhttps://github.com/medialize/URI.js/releases/tag/v1.19.6 (fix for this particular bypass)\nhttps://github.com/medialize/URI.js/releases/tag/v1.19.4 (fix for related bypass)\nhttps://github.com/medialize/URI.js/releases/tag/v1.19.3 (fix for related bypass)\n[PR #233](https://github.com/medialize/URI.js/pull/233) (initial fix for backslash handling)\n\n### For more information\nIf you have any questions or comments about this advisory, open an issue in https://github.com/medialize/URI.js\n\n### Reporter credit\n[Yaniv Nizry](https://twitter.com/ynizry) from the CxSCA AppSec team at Checkmarx","aliases":["CVE-2021-27516"],"modified":"2023-11-08T04:05:24.794143Z","published":"2021-03-01T20:03:53Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2021-02-26T21:37:41Z","nvd_published_at":"2021-02-22T00:15:00Z","cwe_ids":["CWE-20"],"severity":"HIGH"},"references":[{"type":"WEB","url":"https://github.com/medialize/URI.js/security/advisories/GHSA-p6j9-7xhc-rhwp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-27516"},{"type":"WEB","url":"https://github.com/medialize/URI.js/commit/a1ad8bcbc39a4d136d7e252e76e957f3ece70839"},{"type":"WEB","url":"https://advisory.checkmarx.net/advisory/CX-2021-4305"},{"type":"PACKAGE","url":"https://github.com/medialize/URI.js"},{"type":"WEB","url":"https://github.com/medialize/URI.js/releases/tag/v1.19.6"}],"affected":[{"package":{"name":"urijs","ecosystem":"npm","purl":"pkg:npm/urijs"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.19.6"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/03/GHSA-p6j9-7xhc-rhwp/GHSA-p6j9-7xhc-rhwp.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"}]}