Survey of Remote TLS Vulnerability Scanning Tools and Snapshot of TLS Use in Banking Sector

With the increasing popularity and real-world use of TLS, the number of vulnerabilities identified in this protocol has also grown. As a result, the protocol has undergone several revisions, with TLS 1.3 being its latest and currently most secure version. In this paper we provide a brief review of some of the most critical vulnerabilities of the earlier versions of TLS (TLS 1.2 and 1.1), and we survey the performance of several popular TLS scanning tools. The paper also provides a summary of our findings obtained by performing remote TLS scanning of the world's 50 largest banks. Contrary to what one would expect, the state of TLS security in the surveyed banks appears to be at (or below) the state of TLS security across the whole WWW. For example, at present less than 50% of the surveyed banks deploy TLS 1.3, while a significant number of them appear vulnerable to some well-known TLS-based attacks.