Cisco Security Advisory – Cisco IOS Software Release, 15.1(2)T is affected by a denial of service (DoS) vulnerability during the TCP establishment phase. The vulnerability could cause embryonic TCP connections to remain in a SYNRCVD or SYNSENT state. Enough embryonic TCP connections in these states could consume system resources and prevent an affected device from accepting or initiating new TCP connections, including any TCP-based remote management access to the device. No authentication is required to exploit this vulnerability. An attacker does not need to complete a three-way handshake to trigger this vulnerability; therefore, this this vulnerability can be exploited using spoofed packets. This vulnerability may be triggered by normal network traffic.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/92728/cisco-sa-20100812-tcp.txt
Source: https://packetstormsecurity.com/files/92728/Cisco-Security-Advisory-20100812-tcp.html