In the CMS I am trying to use an FileIFrameField and restrict it to only uploading PDF files by doing the following:
$fileUpload = new FileIFrameField( 'PDFUpload', 'PDF Brocure' );
$fileUpload->setAllowedExtensions( array( 'pdf' ) );
$fields->addFieldToTab( 'Root.Content.Main', $fileUpload );
But using this lets me upload any file. Are the extra controls you get e.g. setAllowedExtensions() or setAllowedMaxFileSize() only available in the front end and not the CMS?
Forgot to add also that this is SS 3.2.1 :)