PHTN-30-000036 - The Photon operating system must use Transmission Control Protocol (TCP) syncookies.

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A TCP SYN flood attack can cause a denial of service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected and enables the system to continue servicing valid connection requests.

Satisfies: SRG-OS-000142-GPOS-00071, SRG-OS-000420-GPOS-00186


At the command line, run the following commands:

# sed -i -e '/^net.ipv4.tcp_syncookies/d' /etc/sysctl.conf
# echo net.ipv4.tcp_syncookies=1>>/etc/sysctl.conf
# /sbin/sysctl --load

See Also

Item Details

References: CAT|II, CCI|CCI-001095, CCI|CCI-002385, Rule-ID|SV-256512r887210_rule, STIG-ID|PHTN-30-000036, Vuln-ID|V-256512

Plugin: Unix

Control ID: b70cbee681e4ce33730e356831774bb5486adb5ee60a221d3ccb0e5e582d6213