Windows Tomcat Manager GUI non-Admin

To workaround UAC limitations, the Apache Tomcat Monitor GUI app (tomcat8w/tomcatNw) has an embedded manifest to force elevation (requestedExecutionLevel = requireAdministrator). You can view the manifest settings in the Apache Commons Daemon Procrun prunmgr source code.

Because the manifest is embedded, it is a little tricky to run the executable WITHOUT elevating as an administrator. A basic way to run the program without elevation is to wrap it in a batch file that starts with

set __COMPAT_LAYER=RunAsInvoker
C:\path\to\tomcat8w.exe

Read a discussion of the workaround on superuser: Force a program to run without administrator privileges or UAC?

NOTE that running the Tomcat Monitor as non-admin will lack necessary permissions. You must separately grant the user access to manage the related Tomcat service, write to the related procrun registry location for the tomcat instance, and usually write the the Tomcat configuration and deployment directories. Without the necessary permissions, the designated user will not be able to fully manage the selected Tomcat service instance.

Registry paths that may require added user permissions include:

  • HKLM:\SYSTEM\CurrentControlSet\services\YOUR-TOMCAT-INSTANCE
  • HKLM:\SOFTWARE\Wow6432Node\Apache Software Foundation\Procrun 2.0\YOUR-TOMCAT-INSTANCE

The non-registry service permissions can be managed with the sc.exe sdshow and sc.exe sdset commands. Specifically adding an entry for your SID to the SDDL output of sdshow right before the S: audit entries. Something like (A;;GRGX;;;S-1-2-34-…-…-…-…) which grants Allow of Generic-Read and Generic-Execute required by the Tomcat Monitor GUI. A discussion of how to use sc.exe and SDDL is beyond the scope of this blog post, sorry.

This reminds me that the security defaults for Tomcat on Windows are relatively weak. The default service account selected by the Tomcat Windows Installer is “Local System account” which is the highest privilege account on any Windows system. The Windows installer and GUI Manager tool are built with the expectation that SYSTEM will be the service account and that users managing the Tomcat instance will have Administrator-level privileges on the Windows system. It would be preferred to follow the principle of least-privilege and run Tomcat under an account that does not have broad access to the host system.

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About notesbytom

Keeping technology notes on WordPress.com to free up my mind to solve new problems rather than figuring out the same ones repeatedly :-).
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