/usr/share/orthanc/plugins/libServeFolders.so is in orthanc 1.2.0+dfsg-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/orthanc/plugins/../../../lib/orthanc/libServeFolders.so.1.2.0
/usr/share/orthanc/plugins/../../../lib/orthanc/libServeFolders.so.1.2.0