Title

The system must log martian packets. (Cat III impact)

Discussion

Martian packets are packets containing addresses known by the system to be invalid. Logging these messages allows the SA to identify misconfigurations or attacks in progress.

Check Content

Determine if the system is configured to log martian packets. Examine the IPF rules on the system. # ipfstat -i There must be rules that log inbound traffic containing invalid source addresses, which minimally include the system's own addresses and broadcast addresses for attached subnets. For example, consider a system with a single network connection having IP address 192.168.1.10 with a local subnet broadcast address of 192.168.1.255. Packets with source addresses of 192.168.1.10 and 192.168.1.255 must be logged if received by the system from the network connection. The /etc/opt/ipf/ipf.conf file would appear as follows: block in log quick on lan0 from 192.168.1.10 to any block in log quick on lan0 from 192.168.1.255 to any If such rules do not exist, this is a finding.

Fix Text

Configure the system to log martian packets using IPF. Add rules that log inbound traffic containing invalid source addresses, which minimally include the system's own addresses and broadcast addresses for attached subnets. For example, consider a system with a single network connection having IP address 192.168.1.10 with a local subnet broadcast address of 192.168.1.255. Packets with source addresses of 192.168.1.10 and 192.168.1.255 must be logged if received by the system from the network connection. Edit /etc/opt/ipf/ipf.conf and add the following rules, substituting local addresses and interface names: block in log quick on lan0 from 192.168.1.10 to any block in log quick on lan0 from 192.168.1.255 to any Reload the IPF rules. Flush the rules from your ruleset using the -Fa option. The -A option specifies the active rules list. The -f option specifies the rules configuration file to be used: # ipf -Fa -A -f /etc/opt/ipf/ipf.conf

Additional Identifiers

Rule ID: SV-29772r1_rule

Vulnerability ID: V-22418

Group Title: GEN003611

Expert Comments

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