Permissions, Privileges, and Access Controls
Apache Tomcat before 6.0.40, 7.x before 7.0.54, and 8.x before 8.0.6 does not properly constrain the class loader that accesses the XML parser used with an XSLT stylesheet, which allows remote attackers to (1) read arbitrary files via a crafted web application that provides an XML external entity declaration in conjunction with an entity reference, related to an XML External Entity (XXE) issue, or (2) read files associated with different web applications on a single Tomcat instance via a crafted web application.
CWE-264 - Permissions Privileges and Access Controls
CWE 264 (permissions, privileges, and access controls) is not a weakness in and of itself, rather it is a category of weaknesses related to the management of permissions, privileges, and other security features used to perform access control. If not addressed, the weaknesses in this category allow attackers to gain privileges for an unintended sphere of control, access sensitive information, and execute arbitrary commands.