'packet.c in ssh in OpenSSH allows remote attackers to cause a denial of service (crash) by sending an invalid protocol sequence with USERAUTH_SUCCESS before NEWKEYS, which causes newkeys[mode] to be NULL.'
ClearCenter does not consider this a security issue.
This bug affects the OpenSSH client and not the server. This can cause the client to crash when connecting to a malicious server. This is not a denial of service condition.