GHSA-75jv-vfxf-3865: Assemblyline 4 service client vulnerable to Arbitrary Write through path traversal in Client code

The Assemblyline 4 service client (task_handler.py) accepts a SHA-256 value returned by the service server and uses it directly as a local file name.

No validation / sanitisation is performed.

A malicious or compromised server (or any MITM that can speak to client) can return a path-traversal payload such as ../../../etc/cron.d/evil and force the client to write the downloaded bytes to an arbitrary location on disk.