A gaping hole in Amazon.com’s mobile application, now fixed, allowed hackers to have an unlimited number of attempts guessing a person’s password, according to security vendor FireEye. If users enter their password incorrectly 10 times on the Amazon.com website, the company requires them to solve the squiggle of characters known as a CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart). The CAPTCHA is intended to thwart automated programs that will rapidly try different passwords. But Amazon.com did not show a CAPTCHA on its mobile applications for the iOS and Android platforms, allowing unlimited guesses, according to FireEye researchers Min Zheng, Tao Wei and Hui Xue, who wrote of their findings on FireEye’s blog. FireEye notified Amazon.com of the problem on Jan. 30, and Amazon.com told the security company on Feb. 19 it had been fixed.