/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/ is in rt4-extension-authenexternalauth 0.25-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/html/
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/html/Callbacks/
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/html/Callbacks/ExternalAuth/
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/html/Callbacks/ExternalAuth/Elements/
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/html/Callbacks/ExternalAuth/Elements/Header//
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/html/Callbacks/ExternalAuth/Elements/Header/Head
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/html/Callbacks/ExternalAuth/autohandler/
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/html/Callbacks/ExternalAuth/autohandler/Auth
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/html/Callbacks/ExternalAuth/autohandler/Session
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/html/Elements/
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/html/Elements/DoAuth
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/lib/
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/lib/RT/
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/lib/RT/Authen/
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/lib/RT/Authen/ExternalAuth/
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/lib/RT/Authen/ExternalAuth.pm
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/lib/RT/Authen/ExternalAuth/DBI/
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/lib/RT/Authen/ExternalAuth/DBI.pm
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/lib/RT/Authen/ExternalAuth/DBI/Cookie.pm
/usr/share/request-tracker4/plugins/RT-Authen-ExternalAuth/lib/RT/Authen/ExternalAuth/LDAP.pm