This indicates an attack attempt against an Information Disclosure vulnerability in OpenSSH Client.
The vulnerability is caused by an error when the vulnerable software connects with a malicious ssh server. A remote attacker can exploit this to gain private keys from vulnerable clients.
OpenSSH 5.x, 6.x, and 7.x before 7.1p2
Information Disclosure: Remote attackers can gain sensitive information from vulnerable systems.
Apply the most recent upgrade or patch from the vendor: