How to show Vagrant box version used in a particular directory

This data is possible to retrieve but is not exposed, as far as I know, through the Vagrant CLI. Take a look in ~/.vagrant.d/data/machine-index/index for Linux or macOS and I would assume it'd be something like C:\Users\whoever\.vagrant.d\data\machine-index on Windows.

You'll get some unformatted JSON which contains details on every machine Vagrant knows about. If you run the JSON through a pretty-printer/beautifier you'll get one of these for every machine:

"d62342a255436211725abe8fd3c313ea": {
    "local_data_path": "/Users/whoever/mymachine/.vagrant",
    "name": "default",
    "provider": "virtualbox",
    "state": "poweroff",
    "vagrantfile_name": null,
    "vagrantfile_path": "/Users/whoever/mymachine",
    "updated_at": null,
    "extra_data": {
        "box": {
            "name": "ubuntu/xenial64",
            "provider": "virtualbox",
            "version": "20170706.0.0"
        }
    }
},

And the box information associated with your machine is right there. The ubuntu/xenial64 box on the virtualbox provider version 20170706.0.0.

This is kind of an old thread, but I ran into this situation recently that matched the original request, and I discovered an answer that is not listed here:

The vagrant box outdated command lists the current box version number when it tests to see if there is a newer version of the box.

The caveat is that the vagrant box outdated command needs access to the internet to check the current version, which it also outputs.

I only discovered this after I had written this bash script that uses jq to search for the current directory in the ~/.vagrant.d/data/machine-index/index file. I make no guarantees that this will work in your environment:

$ cat ~/scripts/vagrant_box_info.sh
#!/bin/bash

CUR_DIR=`pwd`

JQ_CMD='.machines|to_entries|map(select(.value.vagrantfile_path|test("'$CUR_DIR'$")))[].value.extra_data'

cat ~/.vagrant.d/data/machine-index/index | jq "$JQ_CMD"

$ ~/scripts/vagrant_box_info.sh
{
  "box": {
    "name": "geerlingguy/centos7",
    "provider": "virtualbox",
    "version": "1.2.15"
  }
}
$