This is a security issue because it enables MITM modification of
request bodies that are meant to have integrity guaranteed by chunk
signatures.
In a PUT request using aws-chunked encoding, MinIO ordinarily
verifies signatures at the end of a chunk. This check can be skipped
if the client sends a false chunk size that is much greater than the
actual data sent: the server accepts and completes the request
without ever reaching the end of the chunk + thereby without ever
checking the chunk signature.