CLPR: Security Hardening

This is a roll-up issue for testing and improving the security of the CLPR implementation.

This is a roll-up issue for the CLPR implementation, but it names no files, tests, entry points, or specific security concerns. Start by locating the CLPR implementation and its existing security tests; done would require the security testing and improvements identified by the project maintainers.

Written by the indexing model from the issue text.