According to the API : http://woocommerce.github.io/woocommerce-rest-api-docs/#list-all-products we can filter products by a single attribute. But Is it impossible to search by multiple attributes through API ?
Example : "I want red shirts". Here attribute is color and attribute term is red. To accomplish the search, the query string goes like this : products?category=17&attribute=pa_color&attribute_term=22&
And we get the red shirts only.
But for "I want red medium shirts" , here an additional size attribute with value medium is encountered. And according to the API there is no way to associate both the color and the size attributes in the query string. So the query - 
products?category=17&attribute=pa_color&attribute_term=22&attribute=pa_size&attribute_term=24& 
returns all products from the store
Is there any workaround ?
Try to request like this:
products?attribute=pa_color&attribute_term=51,50&per_page=100
Its worked for me. Latest woocommerce-api wc/v2!
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