/usr/share/postgresql/9.3/contrib/ is in postgresql-9.3-postgis-scripts 2.1.2+dfsg-2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/postgresql/9.3/contrib/postgis-2.1/
/usr/share/postgresql/9.3/contrib/postgis-2.1/legacy.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/legacy_gist.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/legacy_minimal.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/postgis.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/postgis_comments.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/postgis_restore.pl
/usr/share/postgresql/9.3/contrib/postgis-2.1/postgis_upgrade_20_21.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/postgis_upgrade_21_minor.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/raster_comments.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/rtpostgis.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/rtpostgis_legacy.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/rtpostgis_upgrade_20_21.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/rtpostgis_upgrade_21_minor.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/spatial_ref_sys.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/topology.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/topology_comments.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/topology_upgrade_21_minor.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/uninstall_legacy.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/uninstall_postgis.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/uninstall_rtpostgis.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/uninstall_sfcgal.sql
/usr/share/postgresql/9.3/contrib/postgis-2.1/uninstall_topology.sql