(Pwn2Own) Phoenix Contact CHARX SEC-3100 MQTT Protocol JSON Parsing Buffer Overflow Remote Code Execution Vulnerability

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of Phoenix Contact CHARX SEC-3100 devices. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of JSON-encoded arrays. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a buffer. An attacker can leverage this vulnerability to execute code in the context of the charx-ea user.