STIGQter: STIG Summary: SUSE Linux Enterprise Server 15 Security Technical Implementation Guide Version: 1 Release: 2 Benchmark Date: 23 Apr 2021:

The SUSE operating system must be configured to use TCP syncookies.

DISA Rule

SV-234829r622137_rule

Vulnerability Number

V-234829

Group Title

SRG-OS-000142-GPOS-00071

Rule Version

SLES-15-010310

Severity

CAT II

CCI(s)

• CCI-001095 - The information system manages excess capacity, bandwidth, or other redundancy to limit the effects of information flooding types of denial of service attacks.

Weight

10

Fix Recommendation

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

Check Contents

Verify the SUSE operating system is configured to use IPv4 TCP syncookies.

Check to see if syncookies are used with 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 nothing is returned, this is a finding.

Vulnerability Number

V-234829

Documentable

False

Rule Version

SLES-15-010310

Severity Override Guidance

Verify the SUSE operating system is configured to use IPv4 TCP syncookies.

Check to see if syncookies are used with 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 nothing is returned, this is a finding.

Check Content Reference

M

Target Key

5274

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