The rsync daemon in F5 BIG-IP 11.6 before 11.6.0, 11.5.1 before HF3, 11.5.0 before HF4, 11.4.1 before HF4, 11.4.0 before HF7, 11.3.0 before HF9, and 11.2.1 before HF11 and Enterprise Manager 3.x before 3.1.1 HF2, when configured in failover mode, does not require authentication, which allows remote attackers to read or write to arbitrary files via a cmi request to the ConfigSync IP address.