East-EE, a security researcher, has discovered that Google’s reCAPTCHA is susceptible to a robot attack that leverages its own speech recognition service.
In 2016, another team of security researchers from Columbia University, identified flaws in the technology that would enable hackers to influence the risk analysis, bypass restrictions, and deploy large-scale attacks. Source.
East-EE posted a proof-of-concept script of the hack on GitHub. Using the Python programming language which enables an attacker to automatically bypass reCAPTCHA fields used to protect websites from spam and bot traffic. ReBreakCaptcha works in three stages, which you can find on East-EE’s blog.