Researchers discovered more than a dozen flaws in Uber app and websites, many of them allow hackers to access driver and passenger info. The researchers discovered a total of security 14 issues, four of which cannot be disclosed. One of the vulnerabilities exists in the promotion codes, the riders.uber.com website did not implement security mechanisms to defeat brute-force attacks, allowing attackers to try all possible combinations of strings until the. promotion codes havent been discovered. Researchers also found a $100 ERH (emergency ride home) code that could be applied on top of other promo codes.”]
Source: https://securityaffairs.co/wordpress/48666/hacking/uber-app-flaws.html