A user with contributor rights trying to upload a file with any of the above mentioned extensions will generate a modal dialog "Error: Access Denied" appears. User cannot upload the .SWF file".
Users with designer permissions can upload SWF files successfully in SharePoint 2010. More precisely, the "Add and Customize Pages" permission is required.
Users with contributor permissions could upload SWF files in WSS 3.0 or MOSS 2007.
In Sharepoint 2010, SWF is not by default in the "Blocked File Types" list of a web application but instead has been added to a list of web files considered as web sensitive. These files are listed in the WebFileExtensions property of the WebApplication. The WebFileExtensions property can be programmatically edited, for example using powershell. See WebFileExtensions for more details.