XWiki Platform: Path traversal via resources parameter in ssx and jsx endpoints when using leading slash

XWiki Platform is a generic wiki platform. Versions prior to 18.1.0-rc-1, 17.10.3, 17.4.9, and 16.10.17 allow access to read configuration files by using URLs such as http://localhost:8080/bin/ssx/Main/WebHome?resource=/../../WEB-INF/xwiki.cfg&minify=false, leading to Path Traversal. The vulnerability is can be exploited via resources parameter the ssx and jsx endpoints by using leading slashes. This issue has been patched in 18.1.0-rc-1, 17.10.3, 17.4.9, 16.10.17.