diff --git a/ckanext/fortify/logic/__init__.py b/ckanext/fortify/logic/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/ckanext/fortify/logic/auth/__init__.py b/ckanext/fortify/logic/auth/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/ckanext/fortify/logic/auth/create.py b/ckanext/fortify/logic/auth/create.py
new file mode 100644
index 0000000..ea1e875
--- /dev/null
+++ b/ckanext/fortify/logic/auth/create.py
@@ -0,0 +1,18 @@
+import ckan.plugins.toolkit as toolkit
+
+from ckanext.fortify.logic.auth import helpers
+
+
+@toolkit.chained_auth_function
+def fortify_group_create(next_auth, context, data_dict):
+    return helpers.disallow_non_image_uploads(next_auth, context, data_dict)
+
+
+@toolkit.chained_auth_function
+def fortify_organization_create(next_auth, context, data_dict):
+    return helpers.disallow_non_image_uploads(next_auth, context, data_dict)
+
+
+@toolkit.chained_auth_function
+def fortify_user_create(next_auth, context, data_dict):
+    return helpers.disallow_non_image_uploads(next_auth, context, data_dict)
diff --git a/ckanext/fortify/logic/auth/helpers.py b/ckanext/fortify/logic/auth/helpers.py
new file mode 100644
index 0000000..98313d9
--- /dev/null
+++ b/ckanext/fortify/logic/auth/helpers.py
@@ -0,0 +1,23 @@
+import logging
+
+from ckan.common import _, request
+
+log = logging.getLogger(__name__)
+invalid_filetype_response = {'success': False, 'msg': _('Invalid filetype')}
+
+
+def disallow_non_image_uploads(next_auth, context, data_dict):
+    try:
+        if request.files:
+            files_dict = dict(request.files)
+            image_upload = files_dict.get('image_upload')
+            if image_upload and image_upload.mimetype and 'image' not in image_upload.mimetype:
+                log.error('User {0} upload attempt blocked - file: {1}'.format(
+                    context['user'],
+                    image_upload
+                ))
+                return invalid_filetype_response
+    except Exception as e:
+        log.error(str(e))
+
+    return next_auth(context, data_dict)
diff --git a/ckanext/fortify/logic/auth/update.py b/ckanext/fortify/logic/auth/update.py
new file mode 100644
index 0000000..900cab8
--- /dev/null
+++ b/ckanext/fortify/logic/auth/update.py
@@ -0,0 +1,18 @@
+import ckan.plugins.toolkit as toolkit
+
+from ckanext.fortify.logic.auth import helpers
+
+
+@toolkit.chained_auth_function
+def fortify_group_update(next_auth, context, data_dict):
+    return helpers.disallow_non_image_uploads(next_auth, context, data_dict)
+
+
+@toolkit.chained_auth_function
+def fortify_organization_update(next_auth, context, data_dict):
+    return helpers.disallow_non_image_uploads(next_auth, context, data_dict)
+
+
+@toolkit.chained_auth_function
+def fortify_user_update(next_auth, context, data_dict):
+    return helpers.disallow_non_image_uploads(next_auth, context, data_dict)
diff --git a/ckanext/fortify/plugin.py b/ckanext/fortify/plugin.py
index f4e6471..62bd1b3 100644
--- a/ckanext/fortify/plugin.py
+++ b/ckanext/fortify/plugin.py
@@ -4,6 +4,10 @@
 import logging
 
 from ckanext.fortify import helpers, validators, blueprint
+from ckanext.fortify.logic.auth import (
+    create as auth_create,
+    update as auth_update
+)
 from ckan.lib.uploader import ALLOWED_UPLOAD_TYPES
 
 config = toolkit.config
@@ -37,6 +41,8 @@ def create(self, entity):
 
     if asbool(config.get('ckan.fortify.block_html_resource_uploads', False)):
         plugins.implements(plugins.IUploader, inherit=True)
+        plugins.implements(plugins.IAuthFunctions)
+
         # IUploader
 
         def get_resource_uploader(self, data_dict):
@@ -47,6 +53,20 @@ def get_resource_uploader(self, data_dict):
                 # Returning None will make sure it uses the CKAN default uploader ResourceUpload
                 return None
 
+        # IAuthFunctions
+
+        def get_auth_functions(self):
+            return {
+                # Create auth function overrides
+                'group_create': auth_create.fortify_group_create,
+                'organization_create': auth_create.fortify_organization_create,
+                'user_create': auth_create.fortify_user_create,
+                # Update auth function overrides
+                'group_update': auth_update.fortify_group_update,
+                'organization_update': auth_update.fortify_organization_update,
+                'user_update': auth_update.fortify_user_update,
+            }
+
     if asbool(config.get('ckan.fortify.enable_anti_csrf_tokens', False)) \
             or asbool(config.get('ckan.fortify.enable_password_policy', False)) \
             or asbool(config.get('ckan.fortify.force_html_resource_downloads', False)):