CVE-2020-1938 is a file read/inclusion vulnerability in the AJP connector in Apache Tomcat. This is enabled by default with a default configuration port of 8009. A remote, unauthenticated attacker could exploit this vulnerability to read web application files from a vulnerable server. In instances where the vulnerable server allows file uploads, an attacker could upload malicious JavaServer Pages (JSP) code within a variety of file types and trigger this vulnerability to gain remote code execution (RCE).
It was fixed in Apache Tomcat 9 before version 9.0.31, Tomcat 8 before version 8.5.51, and Tomcat 7 before version 7.0.100.