CVE-2018-8014

The defaults settings for the CORS filter provided in Apache Tomcat 9.0.0.M1 to 9.0.8, 8.5.0 to 8.5.31, 8.0.0.RC1 to 8.0.52, 7.0.41 to 7.0.88 are insecure and enable ‘supportsCredentials’ for all origins. It is expected that users of the CORS filter will have configured it appropriately for their environment rather than using it in the default configuration. Therefore, it is expected that most users will not be impacted by this issue.

Mitigation

When using the CORS filter, it is recommended to configure it explicitly for your environment. In particular, the combination of cors.allowed.origins = * and cors.support.credentials = True should be avoided as this can leave your application vulnerable to cross-site scripting (XSS). For details on configuring CORS filter, please refer to <https://tomcat.apache.org/tomcat-7.0-doc/config/filter.html#CORS_Filter&gt;