RHEL 9 must be configured to use TCP syncookies.
An XCCDF Rule
Description
Denial of service (DoS) is a condition when 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. Satisfies: SRG-OS-000480-GPOS-00227, SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00071
- ID
- SV-257957r1045009_rule
- Version
- RHEL-09-253010
- Severity
- Medium
- References
- Updated
Remediation Templates
A Manual Procedure
Configure RHEL 9 to use TCP syncookies.
Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory:
net.ipv4.tcp_syncookies = 1
Load settings from all system configuration files with the following command: