{"id":"GHSA-5hm8-vh6r-2cjq","summary":"CodeIgniter Shield Vulnerable to SameSite Attackers Bypassing the CSRF Protection","details":"### Impact\nThis 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.\n\nFor 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/`).\n\nThis vulnerability exists whether `Config\\Security::$csrfProtection` is `'cookie'` or `'session'`.\nIt is also exploitable whether `Config\\Security::$regenerate` is `true` or `false`.\n\n### Patches\nUpgrade to **CodeIgniter v4.2.3 or later** and **Shield v1.0.0-beta.2 or later**.\n\n### Workarounds\nDo all of the following:\n- set `Config\\Security::$csrfProtection` to `'session'`\n- remove old session data right after login (immediately after ID and password match)\n- regenerate CSRF token right after login (immediately after ID and password match)\n\n### References\n- [CodeIgniter4 CSRF Protection](https://codeigniter4.github.io/userguide/libraries/security.html)\n- [SameSite Attacks](https://canitakeyoursubdomain.name/)\n- [SameSite Cookies](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie/SameSite)\n- [The great SameSite confusion](https://jub0bs.com/posts/2021-01-29-great-samesite-confusion/)\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue or discussion in [codeigniter4/shield](https://github.com/codeigniter4/shield)\n* Email us at [security@codeigniter.com](mailto:security@codeigniter.com)\n","aliases":["BIT-codeigniter-2022-35943","CVE-2022-35943"],"modified":"2023-12-06T00:47:23.526125Z","published":"2022-08-18T19:03:34Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2022-08-18T19:03:34Z","nvd_published_at":"2022-08-12T21:15:00Z","cwe_ids":["CWE-352"],"severity":"MODERATE"},"references":[{"type":"WEB","url":"https://github.com/codeigniter4/shield/security/advisories/GHSA-5hm8-vh6r-2cjq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-35943"},{"type":"WEB","url":"https://github.com/codeigniter4/shield/commit/342a368536678621998c3c41d276480cd14ec6c6"},{"type":"WEB","url":"https://codeigniter4.github.io/userguide/libraries/security.htm"},{"type":"WEB","url":"https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie/SameSite"},{"type":"PACKAGE","url":"https://github.com/codeigniter4/shield"},{"type":"WEB","url":"https://jub0bs.com/posts/2021-01-29-great-samesite-confusion"}],"affected":[{"package":{"name":"codeigniter4/shield","ecosystem":"Packagist","purl":"pkg:composer/codeigniter4/shield"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.0.0-beta"},{"fixed":"1.0.0-beta.2"}]}],"versions":["1.0.0-beta","v1.0.0-beta"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2022/08/GHSA-5hm8-vh6r-2cjq/GHSA-5hm8-vh6r-2cjq.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:L"}]}