So according to #AMD the vulnerabilities revealed by CTS labs are real and will be fixed via firmware patches and bios updates, they don't expect any performance impact, however they do mention that since admin access is already required to exploit these the unauthorized individual would already have the right to create, delete, or modify any file or folder on the system.

overclock3d.net/news/cpu_mainboard/amd_responds_to_cts_labs_vulnerabilities_-_impact_assessment/1