Ride-hailing app Uber has reportedly ignored a security flaw -- discovered by a New Delhi-based security researcher -- that can allow an attacker to hack into user accounts via bypassing its two-factor authentication feature. "Two-factor authentication is a vital part of protecting online accounts that adds a second layer of security on top of your username and password -- which can be be stolen -- by sending a code by text message to your phone which only you would have access to," tech website ZDNet reported late on Sunday.