CVE-2022-24712 is a Cross-Site Request Forgery (CSRF) vulnerability affecting CodeIgniter4, a popular PHP full-stack web framework widely used for developing web applications. The vulnerability exists in versions prior to 4.1.9 and allows remote attackers to bypass the built-in CSRF protection mechanism. CSRF attacks trick authenticated users into submitting unwanted requests to a web application, potentially causing unauthorized actions such as data modification or state changes without the user's consent. The root cause of this vulnerability is related to the framework's handling of routing and request methods, especially when auto-routing is enabled. Auto-routing allows the framework to automatically map HTTP requests to controller methods without explicit route definitions. If auto-routing is enabled, the framework does not sufficiently verify the HTTP request method before processing, enabling attackers to craft malicious requests that bypass CSRF tokens. When auto-routing is disabled, improper use of route definitions (e.g., using $routes->add() without specifying HTTP verbs) can also lead to CSRF protection bypass. The recommended fix is to upgrade to CodeIgniter4 version 4.1.9 or later, which addresses this issue. However, even after upgrading, developers must implement additional safeguards such as explicitly checking the HTTP request method in controller methods or using HTTP verb-specific routing to ensure CSRF tokens are properly validated. This vulnerability does not require user interaction beyond the victim being authenticated, and exploitation can lead to unauthorized state-changing actions on vulnerable web applications. No known exploits are reported in the wild as of the published date, but the risk remains significant due to the widespread use of CodeIgniter4 in web development.

For European organizations, the impact of this vulnerability can be substantial, particularly for those relying on CodeIgniter4 for internal or customer-facing web applications. Successful exploitation could allow attackers to perform unauthorized actions such as changing user settings, submitting fraudulent transactions, or manipulating application data, potentially leading to data integrity issues, unauthorized access, or service disruption. Sectors such as finance, healthcare, government, and e-commerce, which often use PHP frameworks for web services, could face reputational damage, regulatory penalties (e.g., GDPR non-compliance due to unauthorized data manipulation), and operational disruptions. Since CSRF attacks exploit authenticated sessions, organizations with high-value user accounts or privileged administrative interfaces are at greater risk. The vulnerability's impact is amplified in environments where auto-routing is enabled or where developers have not implemented strict HTTP method checks, increasing the attack surface. Additionally, the need for manual code adjustments after upgrading means that incomplete remediation could leave applications vulnerable, prolonging exposure. Given the absence of known exploits, proactive patching and code review are critical to prevent potential targeted attacks, especially as threat actors often weaponize such vulnerabilities once publicly disclosed.

1. Upgrade all CodeIgniter4 instances to version 4.1.9 or later immediately to incorporate the official patch addressing this vulnerability. 2. Review and audit all routing configurations: disable auto-routing where possible to reduce attack surface. 3. For applications that require auto-routing, implement explicit checks of the HTTP request method within controller methods to ensure that only intended HTTP verbs (e.g., POST for state-changing actions) are processed. 4. Avoid using generic route definitions such as $routes->add() without specifying HTTP verbs; instead, define routes with explicit HTTP methods (e.g., $routes->post(), $routes->get()) to enforce correct request handling. 5. Conduct a thorough code review to verify that CSRF tokens are validated on all state-changing requests and that no endpoints bypass CSRF protection. 6. Implement security testing, including automated and manual penetration testing focused on CSRF attack vectors, to validate the effectiveness of mitigations. 7. Educate development teams on secure routing practices and the importance of CSRF protection mechanisms. 8. Monitor web application logs for unusual or unexpected requests that could indicate attempted CSRF exploitation. 9. Consider implementing additional security controls such as SameSite cookies and Content Security Policy (CSP) headers to reduce CSRF risks. 10. Establish a patch management process to ensure timely updates of web frameworks and dependencies.