A vulnerability in Crater Invoice allows an unauthenticated attacker with knowledge of the APP_KEY to achieve remote command execution on the server by manipulating the laravel_session cookie, exploiting arbitrary deserialization through the encrypted session data. The exploitation vector of this vulnerability relies on an attacker obtaining Laravels secret APP_KEY, which would allow them to decrypt and manipulate session cookies (laravel_session) containing serialized data. By altering this data and re-encrypting it with the APP_KEY, the attacker could trigger arbitrary deserialization on the server, potentially leading to remote command execution (RCE). The vulnerability is primarily exploited by accessing an exposed cookie and manipulating it using the secret key to gain malicious access to the server.
The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
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.