Open-iSCSI rtslib-fb through 2.1.72 has weak permissions for /etc/target/saveconfig.json because shutil.copyfile (instead of shutil.copy) is used, and thus permissions are not preserved.
{ "binaries": [ { "binary_name": "python3-rtslib-fb", "binary_version": "2.1.71-0ubuntu1.1" } ] }