When using a VirtualDirContext with Apache Tomcat 7.0.0 to 7.0.80 it was possible to bypass security constraints and/or view the source code of JSPs for resources served by the VirtualDirContext using a specially crafted request.
https://www.synology.com/support/security/Synology_SA_17_54_Tomcat
https://usn.ubuntu.com/3665-1/
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03828en_us
https://security.netapp.com/advisory/ntap-20171018-0001/
https://lists.debian.org/debian-lts-announce/2018/06/msg00008.html
https://access.redhat.com/errata/RHSA-2018:0466
https://access.redhat.com/errata/RHSA-2018:0465