| A TCP SYN flood attack can cause Denial of Service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies are a mechanism used to not track a connection until a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This technique does not operate in a fully standards-compliant manner, but is only activated when a flood condition is detected, and allows defense of the system while continuing to service valid requests. Permanent finding - The vSphere management network provides access to the vSphere management interface on each component. Services running on the management interface provide an opportunity for an attacker to gain privileged access to the systems. Any remote attack most likely would begin with gaining entry to this network. The vSphere management port group should be in a dedicated VLAN on a common vSwitch. The vSwitch can be shared with production (virtual machine) traffic, as long as the vSphere management port group's VLAN is not used by production virtual machines. Check that the network segment is not routed, except possibly to networks where other management-related entities are found. Production virtual machine traffic must not be routed to this network. |
