Solspace Freeform query for submission assets returns all site assets
The following template code resolved this issue for me:

{% for field in submission.fieldMetadata %}
     {% if field.type == "file" %}
        {% set assetIds = attribute(submission, field.handle).value %}
        {% if assetIds %}
           {% for assetId in assetIds %}
              {% set asset = craft.assets.id(assetId).one() %}
              {% if asset %}
                 {% if asset.kind == "image" %}
                    &lt;img src="{{ asset.url }}" /&gt;
                 {% else %}
                    &lt;a href="{{ asset.url }}"&gt;{{ asset.filename }}&lt;/a&gt;
                 {% endif %}
              {% endif %}
           {% endfor %}
        {% endif %}

     {% else %}
        {{ attribute(submission, field.handle) }}
     {% endif %}
{% endfor %}