The Cisco router must be configured to produce audit records containing information to establish the source of the events.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-96709	CISC-RT-000220	SV-105847r1_rule		Medium

Description
Without establishing the source of the event, it is impossible to establish, correlate, and investigate the events leading up to an outage or attack. In order to compile an accurate risk assessment and provide forensic analysis, security personnel need to know the source of the event. In addition to logging where events occur within the network, the audit records must also identify sources of events such as IP addresses, processes, and node or device names.

Description

Without establishing the source of the event, it is impossible to establish, correlate, and investigate the events leading up to an outage or attack. In order to compile an accurate risk assessment and provide forensic analysis, security personnel need to know the source of the event. In addition to logging where events occur within the network, the audit records must also identify sources of events such as IP addresses, processes, and node or device names.

STIG	Date
Cisco IOS XR Router RTR Security Technical Implementation Guide	2019-12-20

Details

Check Text ( C-95545r1_chk )
Review the router configuration to verify that events are logged containing information to establish the source of the events as shown in the example below. ipv4 access-list EXTERNAL_ACL_INBOUND 10 permit tcp host x.11.1.1 eq bgp host x.11.1.2 20 permit tcp host x.11.1.1 host x.11.1.2 eq bgp 25 deny icmp any host x.11.1.2 fragments log 30 permit icmp host x.11.1.1 host x.11.1.2 echo 40 permit icmp host x.11.1.1 host x.11.1.2 echo-reply 50 deny ipv4 any host x.11.1.1 log-input 60 permit tcp any any established … … … 140 deny ipv4 any any log-input Note: When the log-input parameter is configured on deny statements, the log record will contain the layer 2 address of the forwarding device for any packet being dropped. If the router is not configured to produce audit records containing information to establish the source of the events, this is a finding.

Check Text ( C-95545r1_chk )

Review the router configuration to verify that events are logged containing information to establish the source of the events as shown in the example below.

ipv4 access-list EXTERNAL_ACL_INBOUND
10 permit tcp host x.11.1.1 eq bgp host x.11.1.2
20 permit tcp host x.11.1.1 host x.11.1.2 eq bgp
25 deny icmp any host x.11.1.2 fragments log
30 permit icmp host x.11.1.1 host x.11.1.2 echo
40 permit icmp host x.11.1.1 host x.11.1.2 echo-reply
50 deny ipv4 any host x.11.1.1 log-input
60 permit tcp any any established
…
…
…
140 deny ipv4 any any log-input

Note: When the log-input parameter is configured on deny statements, the log record will contain the layer 2 address of the forwarding device for any packet being dropped.

If the router is not configured to produce audit records containing information to establish the source of the events, this is a finding.

Fix Text (F-102387r1_fix)
Configure the router to log events containing information to establish where the events occurred as shown in the example below. RP/0/0/CPU0:R3(config)#ipv4 access-list EXTERNAL_ACL_INBOUND … … … RP/0/0/CPU0:R3(config-ipv4-acl)#deny ip any any log-input