Описание
Hostname spoofing via backslashes in URL
Impact
If using affected versions to determine a URL's hostname, the hostname can be spoofed by using a backslash (\) character followed by an at (@) character. 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\@observed-example.com
Escaped string: https://expected-example.com\\@observed-example.com (JavaScript strings must escape backslash)
Affected versions incorrectly return observed-example.com. 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 1.19.4 is patched against all known payload variants. Version 1.19.3 has a partial patch but is still vulnerable to a payload variant.
References
https://github.com/medialize/URI.js/releases/tag/v1.19.4 (complete fix for this bypass) https://github.com/medialize/URI.js/releases/tag/v1.19.3 (partial fix for this 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
Ссылки
- https://github.com/medialize/URI.js/security/advisories/GHSA-3329-pjwv-fjpg
- https://nvd.nist.gov/vuln/detail/CVE-2020-26291
- https://github.com/medialize/URI.js/commit/b02bf037c99ac9316b77ff8bfd840e90becf1155
- https://github.com/medialize/URI.js/releases/tag/v1.19.4
- https://www.npmjs.com/advisories/1595
- https://www.npmjs.com/package/urijs
Пакеты
urijs
< 1.19.4
1.19.4
Связанные уязвимости
URI.js is a javascript URL mutation library (npm package urijs). In URI.js before version 1.19.4, the hostname can be spoofed by using a backslash (`\`) character followed by an at (`@`) character. 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. For example the URL `https://expected-example.com\@observed-example.com` will incorrectly return `observed-example.com` if using an affected version. 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. Version 1.19.4 is patched against all known payload variants. Version 1.19.3 has a partial patch but is still vulnerable to a payload variant.]
URI.js is a javascript URL mutation library (npm package urijs). In URI.js before version 1.19.4, the hostname can be spoofed by using a backslash (`\`) character followed by an at (`@`) character. 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. For example the URL `https://expected-example.com\@observed-example.com` will incorrectly return `observed-example.com` if using an affected version. 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. Version 1.19.4 is patched against all known payload variants. Version 1.19.3 has a partial patch but is still vulnerable to a payload variant.]
URI.js is a javascript URL mutation library (npm package urijs). In UR ...