The server http://api.tapplock.com/ which servers as the api server for the tapplock smart lock is vulnerable to multiple authorization bypasses allowing horizontal escalation of privileges which could lead to the disclosure of all the info of all users and  total compromise of every lock. The attacker could gain access to any lock, and retrieve PII (email and street address) of any user.
There is a full write up available at : https://medium.com/@evstykas/totally-pwning-the-tapplock-smart-lock-the-api-way-c8d89915f025 <https://medium.com/@evstykas/totally-pwning-the-tapplock-smart-lock-the-api-way-c8d89915f025>


Details

Attack Vector: HTTP GET
Prerequisites: Authentication (Authorization Header)
CWE: Insecure Direct Object References, Authorization bypass through user-controlled key
Technical Impact: Horizontal escalation of privilege (one user can view/modify information of all accounts)
Vulnerable query URLs:
http://api.tapplock.com/api/v1/locks/{email}?myOwner=0&page=1&size=10
http://api.tapplock.com/api/v1/shareable_users/{email}?page=1&size=10
http://api.tapplock.com/api/v1/shares/{email}?page=1&size=10
Vulnerable  parameter: email


Attack Vector: HTTP GET
Prerequisites: Authentication (Authorization Header)
CWE: Insecure Direct Object References, Authorization bypass through user-controlled key
Technical Impact: Horizontal escalation of privilege (one user can view/modify information of all accounts)
Vulnerable query URLs:
http://api.tapplock.com/api/v1/locks/{email}?myOwner=0&page=1&size=10
http://api.tapplock.com/api/v1/shareable_users/{email}?page=1&size=10
http://api.tapplock.com/api/v1/shares/{email}?page=1&size=10
Vulnerable parameter: email

Attack Vector: HTTP GET
Prerequisites: Authentication (Authorization Header)
CWE: Insecure Direct Object References, Authorization bypass through user-controlled key
Technical Impact: Horizontal escalation of privilege (one user can view/modify information of all accounts)
Vulnerable query URLs:
http://api.tapplock.com/api/v1/finger_owners/{userUuid}?page=1&size=10
http://api.tapplock.com/api/v1/unlock_records/bluetooth/{userUuid}?page=1&size=10
http://api.tapplock.com/api/v1/finger_owners/{userUuid}?page=1&size=10
Vulnerable parameter: userUuid

Attack Vector: HTTP POST
Prerequisites: Authentication (Authorization Header)
CWE: Insecure Direct Object References, Authorization bypass through user-controlled key
Technical Impact: Horizontal escalation of privilege (one user can view/modify information of all accounts)
Vulnerable query URLs:
http://api.tapplock.com/api/v1/users
http://api.tapplock.com/api/v1/locks
http://api.tapplock.com/api/v1/shareable_users
http://api.tapplock.com/api/v1/shares
http://api.tapplock.com/api/v1/finger_owners
http://api.tapplock.com/api/v1/fingers
http://api.tapplock.com/api/v1/fingers/actions/check
http://api.tapplock.com/api/v1/unlock_records/bluetooth
Vulnerable parameter: All the parameters that are posted on the json payload are not checked.


Attack Vector: HTTP PATCH
Prerequisites: Authentication (Authorization Header)
CWE: Insecure Direct Object References, Authorization bypass through user-controlled key
Technical Impact: Horizontal escalation of privilege (one user can view/modify information of all accounts)
Vulnerable query URLs:
http://api.tapplock.com/api/v1/users
http://api.tapplock.com/api/v1/locks
http://api.tapplock.com/api/v1/shareable_users
Vulnerable parameter: All the parameters that are posted on the json payload are not checked.

Attack Vector: HTTP DELETE
Prerequisites: Authentication (Authorization Header)
CWE: Insecure Direct Object References, Authorization bypass through user-controlled key
Technical Impact: Horizontal escalation of privilege (one user can view/modify information of all accounts)
Vulnerable query URLs:
http://api.tapplock.com/api/v1/locks/{lockId}
http://api.tapplock.com/api/v1/finger_owners/{uuid}
http://api.tapplock.com/api/v1/shareable_users/{shareableUserId}
http://api.tapplock.com/api/v1/shares/{shareId}
http://api.tapplock.com/api/v1/fingers/{fingerprintId}

Vulnerable parameter: All the parameters in {} are vulnerable.