Cisco Security Advisory – The SSH server implementation in Cisco IOS XR Software contains a vulnerability that an unauthenticated, remote user could exploit to cause a denial of service condition. An attacker could trigger this vulnerability by sending a crafted SSH version 2 packet that may cause a new SSH connection handler process to crash. Repeated exploitation may cause each new SSH connection handler process to crash and lead to a significant amount of memory being consumed, which could introduce instability that may adversely impact other system functionality. During this event, the parent SSH daemon process will continue to function normally.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/85435/cisco-sa-20100120-xr-ssh.txt
Source: https://packetstormsecurity.com/files/85435/Cisco-Security-Advisory-20100120-xr-ssh.html