Severity: Critical
CVSS Score: 10
### Impact EPyT-Flow’s REST API parses attacker-controlled JSON request bodies using a custom deserializer (my_load_from_json) that supports a __type__ field. When __type__ is present, the deserializer dynamically imports an attacker-specified module/class and instantiates it with attacker-supplied arguments. This allows invoking dangerous classes such as subprocess.Popen, which can lead to OS command execution during JSON parsing. This also affects the loading of JSON files. ### Patches EPyT-Flow has been patched in 0.16.1 -- affects all versions <= 0.16.0 ### Workarounds Do not load any JSON from untrusted sources and do not expose the REST API. ### Credits EPyT-Flow thanks Jarrett Chan (@syphonetic) for detecting and reporting the bug.