GitHub Advisoryadvisory · npm
GHSA-89gv-h8wf-cg8r URIjs Vulnerable to Hostname spoofing via backslashes in URL
MEDIUM
Official page ↗
- Aliases
- CVE-2021-3647
- Ecosystem
- npm
- Packages
- urijs
- Severity
- Moderate
- CVSS vector
- CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- Weaknesses
- CWE-601
- Reviewed
- 2021-07-19
Affected packages
• npm urijs: < 1.19.7 → fixed in 1.19.7
Description
Impact
If using affected versions to determine a URL's hostname, the hostname can be spoofed by using a combination of backslash (`\`) and slash (`/`) characters as part of the scheme delimiter, e.g. `scheme:/\/\/\hostname`. If the hostname is used in security decisions, the decision may be incorrect.
Depending on library usage and attacker intent, impacts may include allow/block list bypasses, SSRF attacks, open redirects, or other undesired behavior.
Example URL: `https:/\/\/\expected-example.com/path`
Escaped string: `https:/\\/\\/\\expected-example.com/path` (JavaScript strings must escape backslash)
Affected 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, including web browsers and Node's built-in URL class.
Patches
Version 1.19.7 is patched against all known payload variants.
References
https://github.com/medialize/URI.js/releases/tag/v1.19.7 (fix for this particular bypass)
https://github.com/medialize/URI.js/releases/tag/v1.19.6 (fix for related bypass)
https://github.com/medialize/URI.js/releases/tag/v1.19.4 (fix for related bypass)
https://github.com/medialize/URI.js/releases/tag/v1.19.3 (fix for related bypass)
PR #233 (initial fix for backslash handling)
For more information
If you have any questions or comments about this advisory, open an issue in https://github.com/medialize/URI.js
Reporter credit
ready-research via https://huntr.dev/
Related
Alias · CVE (1)
- CVE-2021-3647 URI.js is vulnerable to URL Redirection to Untrusted Site vulnerability
Weakness · CWE (1)
- CWE-601 URL Redirection to Untrusted Site weakness
References
- https://github.com/medialize/URI.js/security/advisories/GHSA-89gv-h8wf-cg8r web
- https://nvd.nist.gov/vuln/detail/CVE-2021-3647 advisory
- https://github.com/medialize/URI.js/pull/233 web
- https://github.com/medialize/URI.js/commit/ac43ca8f80c042f0256fb551ea5203863dec4481 web
- https://github.com/medialize/URI.js/releases/tag/v1.19.3 web
- https://github.com/medialize/URI.js/releases/tag/v1.19.4 web
- https://github.com/medialize/URI.js/releases/tag/v1.19.6 web
- https://github.com/medialize/URI.js/releases/tag/v1.19.7 web
- https://huntr.dev/bounties/1625558772840-medialize/URI.js web