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V-256572

CAT II (Medium)

The Photon operating system must log IPv4 packets with impossible addresses.

Rule ID

SV-256572r991589_rule

STIG

VMware vSphere 7.0 vCenter Appliance Photon OS Security Technical Implementation Guide

Version

V1R4

CCIs

CCI-000366

Discussion

The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.

Check Content

At the command line, run the following command:

# /sbin/sysctl -a --pattern "net.ipv4.conf.(all|default|eth.*).log_martians"

Expected result:

net.ipv4.conf.all.log_martians = 1
net.ipv4.conf.default.log_martians = 1
net.ipv4.conf.eth0.log_martians = 1

If the output does not match the expected result, this is a finding.

Note: The number of "ethx" lines returned is dependent on the number of interfaces. Every "ethx" entry must be set to "1".

Fix Text

At the command line, run the following command:

# for SETTING in $(/sbin/sysctl -aN --pattern "net.ipv4.conf.(all|default|eth.*).log_martians"); do sed -i -e "/^${SETTING}/d" /etc/sysctl.conf;echo $SETTING=1>>/etc/sysctl.conf; done
# /sbin/sysctl --load