Description
The Mapper component in Apache Tomcat 6.x before 6.0.45, 7.x before 7.0.68, 8.x before 8.0.30, and 9.x before 9.0.0.M2 processes redirects before considering security constraints and Filters, which allows remote attackers to determine the existence of a directory via a URL that lacks a trailing / (slash) character.
Mitigation
We recommend upgrading to a version of this component that is not vulnerable to this specific issue.