CodeIgniter Shield Vulnerable to SameSite Attackers Bypassing the CSRF Protection
The advisory, in context
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::$csrfProtectionto'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
For more information
If you have any questions or comments about this advisory:
- Open an issue or discussion in codeigniter4/shield
- Email us at security@codeigniter.com
Affected packages
Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.
From 1.0.0-beta before 1.0.0-beta.2
Fixed in 1.0.0-beta.2
2 explicitly affected versions
1.0.0-beta, v1.0.0-beta
View affected-version evidence
{
"ranges": [
{
"events": [
{
"introduced": "1.0.0-beta"
},
{
"fixed": "1.0.0-beta.2"
}
],
"type": "ECOSYSTEM"
}
],
"versions": [
"1.0.0-beta",
"v1.0.0-beta"
]
}References
- https://github.com/codeigniter4/shield/security/advisories/GHSA-5hm8-vh6r-2cjq
- https://nvd.nist.gov/vuln/detail/CVE-2022-35943
- https://github.com/codeigniter4/shield/commit/342a368536678621998c3c41d276480cd14ec6c6
- https://codeigniter4.github.io/userguide/libraries/security.htm
- https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie/SameSite
- https://github.com/codeigniter4/shield
- https://jub0bs.com/posts/2021-01-29-great-samesite-confusion