Streamit <= 4.5.0 - Unauthenticated Remote Code Execution via Arbitrary Function Call

Description

The theme does not perform any authorization or nonce verification on one of its unauthenticated AJAX routes, which invokes an attacker-supplied PHP function with an attacker-supplied argument array, allowing unauthenticated attackers to call arbitrary functions (for example to create an administrator account), leading to privilege escalation and remote code execution.