The Cisco switch must be configured to use keys with a duration not exceeding 180 days for authenticating routing protocol messages.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-101861	CISC-RT-000030	SV-110965r1_rule		Medium

Description
If the keys used for routing protocol authentication are guessed, the malicious user could create havoc within the network by advertising incorrect routes and redirecting traffic. Some routing protocols allow the use of key chains for authentication. A key chain is a set of keys that is used in succession, with each having a lifetime of no more than 180 days. Changing the keys frequently reduces the risk of them eventually being guessed. Keys cannot be used during time periods for which they are not activated. If a time period occurs during which no key is activated, neighbor authentication cannot occur, and therefore routing updates will fail. Therefore, ensure that for a given key chain, key activation times overlap to avoid any period of time during which no key is activated.

Description

If the keys used for routing protocol authentication are guessed, the malicious user could create havoc within the network by advertising incorrect routes and redirecting traffic. Some routing protocols allow the use of key chains for authentication. A key chain is a set of keys that is used in succession, with each having a lifetime of no more than 180 days. Changing the keys frequently reduces the risk of them eventually being guessed. Keys cannot be used during time periods for which they are not activated. If a time period occurs during which no key is activated, neighbor authentication cannot occur, and therefore routing updates will fail. Therefore, ensure that for a given key chain, key activation times overlap to avoid any period of time during which no key is activated.

STIG	Date
Cisco NX-OS Switch RTR Security Technical Implementation Guide	2020-05-20

Details

Check Text ( C-100749r1_chk )
Review the start times for each key within the configured key chains used for routing protocol authentication as shown in the example below: key chain OSPF_KEY key 1 key-string 7 070d2e4e4c10 accept-lifetime 00:00:00 Oct 01 2019 01:05:00 Jan 01 2020 send-lifetime 00:00:00 Oct 01 2019 23:59:59 Dec 31 2019 key 2 key-string 7 0704205e4b07 accept-lifetime 23:55:00 Dec 31 2019 01:05:00 Apr 01 2020 send-lifetime 00:00:00 Jan 01 2020 23:59:59 Mar 31 2020 Note: Key chains must be configured to authenticate routing protocol messages as it is the only way to set an expiration. If any key has a lifetime of more than 180 days, this is a finding.

Check Text ( C-100749r1_chk )

Review the start times for each key within the configured key chains used for routing protocol authentication as shown in the example below:

key chain OSPF_KEY
key 1
key-string 7 070d2e4e4c10
accept-lifetime 00:00:00 Oct 01 2019 01:05:00 Jan 01 2020
send-lifetime 00:00:00 Oct 01 2019 23:59:59 Dec 31 2019
key 2
key-string 7 0704205e4b07
accept-lifetime 23:55:00 Dec 31 2019 01:05:00 Apr 01 2020
send-lifetime 00:00:00 Jan 01 2020 23:59:59 Mar 31 2020

Note: Key chains must be configured to authenticate routing protocol messages as it is the only way to set an expiration.

If any key has a lifetime of more than 180 days, this is a finding.

Fix Text (F-107543r1_fix)
Configure each key used for routing protocol authentication to have a lifetime of no more than 180 days as shown in the example below: SW1(config)# key chain OSPF_KEY SW1(config-keychain)# key 1 SW1(config-keychain-key)# key-string xxxxxxxxxxxx SW1(config-keychain-key)# send-lifetime 00:00:00 Oct 1 2019 23:59:59 Dec 31 2019 SW1(config-keychain-key)# accept-lifetime 00:00:00 Oct 1 2019 01:05:00 Jan 1 2020 SW1(config-keychain-key)# key 2 SW1(config-keychain-key)# key-string kxxxxxxxxxxxxx SW1(config-keychain-key)# send-lifetime 00:00:00 Jan 1 2020 23:59:59 Mar 31 2020 SW1(config-keychain-key)# accept-lifetime 23:55:00 Dec 31 2019 01:05:00 Apr 1 2020 SW1(config-keychain-key)# end

Fix Text (F-107543r1_fix)

Configure each key used for routing protocol authentication to have a lifetime of no more than 180 days as shown in the example below:

SW1(config)# key chain OSPF_KEY
SW1(config-keychain)# key 1
SW1(config-keychain-key)# key-string xxxxxxxxxxxx
SW1(config-keychain-key)# send-lifetime 00:00:00 Oct 1 2019 23:59:59 Dec 31 2019
SW1(config-keychain-key)# accept-lifetime 00:00:00 Oct 1 2019 01:05:00 Jan 1 2020
SW1(config-keychain-key)# key 2
SW1(config-keychain-key)# key-string kxxxxxxxxxxxxx
SW1(config-keychain-key)# send-lifetime 00:00:00 Jan 1 2020 23:59:59 Mar 31 2020
SW1(config-keychain-key)# accept-lifetime 23:55:00 Dec 31 2019 01:05:00 Apr 1 2020
SW1(config-keychain-key)# end