GHSA-5hm8-vh6r-2cjq CodeIgniter Shield Vulnerable to SameSite Attackers Bypassing the CSRF Protection

• Packagist codeigniter4/shield: >= 1.0.0-beta, < 1.0.0-beta.2 → fixed in 1.0.0-beta.2

Impact This vulnerability may allow SameSite Attackers to bypass the CodeIgniter4 CSRF protection 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/`). This vulnerability exists whether `Config\Security::$csrfProtection` is `'cookie'` or `'session'`. It is also exploitable whether `Config\Security::$regenerate` is `true` or `false`. Patches Upgrade to CodeIgniter v4.2.3 or later and Shield v1.0.0-beta.2 or later. Workarounds Do all of the following: • set `Config\Security::$csrfProtection` to `'session'` • remove old session data right after login (immediately after ID and password match) • regenerate CSRF token right after login (immediately after ID and password match) References • CodeIgniter4 CSRF Protection • SameSite Attacks • SameSite Cookies • The great SameSite confusion For more information If you have any questions or comments about this advisory: • Open an issue or discussion in codeigniter4/shield • Email us at [email protected]