Details

Denial of Service (DoS) is a condition in which a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity.

Managing excess capacity ensures that sufficient capacity is available to counter flooding attacks. Employing increased capacity and service redundancy may reduce the susceptibility to some DoS attacks. Managing excess capacity may include, for example, establishing selected usage priorities, quotas, or partitioning.

Solution

Configure the SUSE operating system to use IPv4 TCP syncookies by running the following command as an administrator:

> sudo sysctl -w net.ipv4.tcp_syncookies=1

If ‘1’ is not the system’s default value, add or update the following line in ‘/etc/sysctl.d/99-stig.conf’:

> sudo sh -c ‘echo ‘net.ipv4.tcp_syncookies=1′ >> /etc/sysctl.d/99-stig.conf’

> sudo sysctl –system

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_SLES_15_V1R3_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Unix.

References

• 800-53|SC-5(2)
• CAT|II
• CCI|CCI-001095
• CSCv6|9.2
• Rule-ID|SV-234829r622137_rule
• STIG-ID|SLES-15-010310
• STIG-Legacy|SV-92181
• STIG-Legacy|V-77485
• Vuln-ID|V-234829

Source

• Tenable.com/audits