Arbitrary File Overwrite in h2oai/h2o-3

In h2oai/h2o-3 version 3.46.0, the `/99/Models/{name}/json` endpoint allows for arbitrary file overwrite on the target server. The vulnerability arises from the `exportModelDetails` function in `ModelsHandler.java`, where the user-controllable `mexport.dir` parameter is used to specify the file path for writing model details. This can lead to overwriting files at arbitrary locations on the host system.