When running on Windows with enableCmdLineArguments enabled, the CGI Servlet in Apache Tomcat 9.0.0.M1 to 9.0.17, 8.5.0 to 8.5.39 and 7.0.0 to 7.0.93 is vulnerable to Remote Code Execution due to a bug in the way the JRE passes command line arguments to Windows. The CGI Servlet is disabled by default. The CGI option enableCmdLineArguments is disable by default in Tomcat 9.0.x (and will be disabled by default in all versions in response to this vulnerability). For a detailed explanation of the JRE behaviour, see Markus Wulftange's blog (https://codewhitesec.blogspot.com/2016/02/java-and-command-line-injections-in-windows.html) and this archived MSDN blog (https://web.archive.org/web/20161228144344/https://blogs.msdn.microsoft.com/twistylittlepassagesallalike/2011/04/23/everyone-quotes-command-line-arguments-the-wrong-way/).
We recommend upgrading to a version of this component that is not vulnerable to this specific issue.
Until a fixed version is installed, the vulnerability can be mitigated by setting the CGI Servlet initialization parameter `enableCmdLineArguments` to false.
NOTE: For 7.0.x, the advisory mentions upgrading to 7.0.93 which appears to be a typographical error as 7.0.93 is not a fixed version. 7.0.94 has been released and this contains the fix.