CVE-2022-35943

CodeIgniter Shield Vulnerable to SameSite Attackers Bypassing the CSRF Protection

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]

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.

A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones. Typical impact: state-changing actions performed as the victim without their consent.

CVE-2022-35943 has a CVSS score of 5.9 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.0.0-beta.2); upgrading removes the vulnerable code path.

Kodem intelligence

Already deployed Kodem?

Upgrade to CodeIgniter v4.2.3 or later and Shield v1.0.0-beta.2 or later.

1. What is CVE-2022-35943? CVE-2022-35943 is a medium-severity cross-site request forgery (CSRF) vulnerability in codeigniter4/shield (composer), affecting versions = 1.0.0-beta. It is fixed in 1.0.0-beta.2. A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones.
2. How severe is CVE-2022-35943? CVE-2022-35943 has a CVSS score of 5.9 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of codeigniter4/shield are affected by CVE-2022-35943? codeigniter4/shield (composer) versions = 1.0.0-beta is affected.
4. Is there a fix for CVE-2022-35943? Yes. CVE-2022-35943 is fixed in 1.0.0-beta.2. Upgrade to this version or later.
5. Is CVE-2022-35943 exploitable, and should I be worried? Whether CVE-2022-35943 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2022-35943 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2022-35943? Upgrade codeigniter4/shield to 1.0.0-beta.2 or later.

Other vulnerabilities in codeigniter4/shield