Check your Cisco appliances and be sure they have the latest updates installed. This week the company released patches for 15 vulnerabilities that affect three different current product lines and may also affect older PIX appliances that are no longer supported. The ASA 550 series, Catalyst 6500 series 7600 Series routers are impacted by these buffer overflow and DoS vulnerabilities. Read more about it here:
http://threatpost.com/en_us/blogs/cisco-patches-rash-buffer-overflow-and-dos-vulnerabilities-101112