Detections
Analytics

3.15 Set Maximum Number of Half-open TCP Connections

Information

This setting controls how many half-open connections can exist for a TCP port.

It is necessary to control the number of completed connections to the system to provide some protection against Denial of Service attacks. Note that the value of 4096 is a minimum to establish a good security posture for this setting. In environments where connection numbers are high, such as a busy webserver, this value may need to be increased.

Solution

To enforce this setting, run the following command:

# ipadm set-prop -p _conn_req_max_q0=4096 tcp

See Also

https://workbench.cisecurity.org/benchmarks/4777

Item Details

Category: SECURITY ASSESSMENT AND AUTHORIZATION, SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|CA-9, 800-53|SC-7, 800-53|SC-7(5), CSCv7|9.4

Plugin: Unix

Control ID: af0e416a850bb220a2b45a70790833c682a402d13eb3e4e98a42e550d68d527c