CodeIgniter is an open source PHP full-stack web framework. Deserialization of Untrusted Data was found in the old() function in CodeIgniter4. Remote attackers may inject auto-loadable arbitrary objects with this vulnerability, and possibly execute existing PHP code on the server. We are aware of a working exploit, which can lead to SQL injection. Users are advised to upgrade to v4.1.6 or later. Users unable to upgrade as advised to not use the old() function and form_helper nor RedirectResponse::withInput() and redirect()->withInput().
The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Codeigniter | Codeigniter | 4.0.0 (including) | 4.1.6 (excluding) |
It is often convenient to serialize objects for communication or to save them for later use. However, deserialized data or code can often be modified without using the provided accessor functions if it does not use cryptography to protect itself. Furthermore, any cryptography would still be client-side security – which is a dangerous security assumption. Data that is untrusted can not be trusted to be well-formed. When developers place no restrictions on “gadget chains,” or series of instances and method invocations that can self-execute during the deserialization process (i.e., before the object is returned to the caller), it is sometimes possible for attackers to leverage them to perform unauthorized actions, like generating a shell.