STIGQter: STIG Summary: Tri-Lab Operating System Stack (TOSS) 5 Security Technical Implementation Guide Version: 1 Release: 1 Benchmark Date: 26 Mar 2026:

TOSS 5 must be configured to use TCP syncookies.

DISA Rule

SV-282512r1201342_rule

Vulnerability Number

V-282512

Group Title

SRG-OS-000142-GPOS-00071

Rule Version

TOSS-05-000212

Severity

CAT II

CCI(s)

• CCI-001095 - Manage capacity, bandwidth, or other redundancy to limit the effects of information flooding types of denial of service attacks.
• CCI-002385 - Protect against or limit the effects of organization-defined types of denial of service events.

Weight

10

Fix Recommendation

Configure TOSS 5 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 using the following command:

$ sudo sysctl --system

Check Contents

Verify TOSS 5 is configured to use IPv4 TCP syncookies using the following command:

$ sudo sysctl net.ipv4.tcp_syncookies

net.ipv4.tcp_syncookies = 1

If the network parameter "ipv4.tcp_syncookies" is not equal to "1" or a line is not returned, this is a finding.

Vulnerability Number

V-282512

Documentable

False

Rule Version

TOSS-05-000212

Severity Override Guidance

Verify TOSS 5 is configured to use IPv4 TCP syncookies using the following command:

$ sudo sysctl net.ipv4.tcp_syncookies

net.ipv4.tcp_syncookies = 1

If the network parameter "ipv4.tcp_syncookies" is not equal to "1" or a line is not returned, this is a finding.

Check Content Reference

M

Target Key

5738