The Cisco CSS 11000 Series is vulnerable to a denial of service when there is a heavy storm of TCP SYN packets directed to the circuit address. It may also cause a high CPU load or sudden reboots.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/31518/s21sec-025-en.txt
Source: https://packetstormsecurity.com/files/31518/s21sec-025-en.txt.html