TechCrunch:

The exposed server belongs to Voxox (formerly Telcentris), a San Diego, Calif.-based communications company. The server wasn’t protected with a password, allowing anyone who knew where to look to peek in and snoop on a near-real-time stream of text messages.

And:

Worse, the database — running on Amazon’s Elasticsearch — was configured with a Kibana front-end, making the data within easily readable, browsable and searchable for names, cell numbers and the contents of the text messages themselves.

And:

Often, app developers — like HQ Trivia and Viber — will employ technologies provided by firms like Telesign and Nexmo, either to verify a user’s phone number or to send a two-factor authentication code, for example. But it’s firms like Voxox that act as a gateway and converting those codes into text messages, to be passed on to the cell networks for delivery to the user’s phone.

Interesting to see how those two-factor requests are outsourced and where those text messages come from. Check out those sample searches in the article. A database like this is searchable in real time, making it easy for someone to monitor changes, steal accounts. A serious point of vulnerability.