When a SecurityManager is configured, a web application's ability to read system properties should be controlled by the SecurityManager. In Apache Tomcat 9.0.0.M1 to 9.0.0.M9, 8.5.0 to 8.5.4, 8.0.0.RC1 to 8.0.36, 7.0.0 to 7.0.70, 6.0.0 to 6.0.45 the system property replacement feature for configuration files could be used by a malicious web application to bypass the SecurityManager and read system properties that should not be visible.
https://www.oracle.com/security-alerts/cpuoct2021.html
https://usn.ubuntu.com/4557-1/
https://security.netapp.com/advisory/ntap-20180605-0001/
https://access.redhat.com/errata/RHSA-2017:2247
https://access.redhat.com/errata/RHSA-2017:0456
https://access.redhat.com/errata/RHSA-2017:0455