Shield is an authentication and authorization framework for CodeIgniter 4. This vulnerability may allow [SameSite Attackers](https://canitakeyoursubdomain.name/) to bypass the [CodeIgniter4 CSRF protection](https://codeigniter4.github.io/userguide/libraries/security.html) mechanism with CodeIgniter Shield. For this attack to succeed, the attacker must have direct (or indirect, e.g., XSS) control over a subdomain site (e.g., `https://a.example.com/`) of the target site (e.g., `http://example.com/`). Upgrade to **CodeIgniter v4.2.3 or later** and **Shield v1.0.0-beta.2 or later**. As a workaround: set `Config\Security::$csrfProtection` to `'session,'`remove old session data right after login (immediately after ID and password match) and regenerate CSRF token right after login (immediately after ID and password match)
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.
| Link | Tags |
|---|---|
| https://github.com/codeigniter4/shield/security/advisories/GHSA-5hm8-vh6r-2cjq | mitigation third party advisory exploit |
| https://codeigniter4.github.io/userguide/libraries/security.htm | broken link |
| https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie/SameSite | third party advisory |
| https://jub0bs.com/posts/2021-01-29-great-samesite-confusion | third party advisory |