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-101585	CISC-RT-000030	SV-110689r1_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 IOS Switch RTR Security Technical Implementation Guide	2020-05-20

Details

Check Text ( C-100471r1_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_CHAIN key 1 key-string xxxxxxx send-lifetime 00:00:00 Jan 1 2018 23:59:59 Mar 31 2018 accept-lifetime 00:00:00 Jan 1 2018 01:05:00 Apr 1 2018 key 2 key-string yyyyyyy send-lifetime 00:00:00 Apr 1 2018 23:59:59 Jun 30 2018 accept-lifetime 23:55:00 Mar 31 2018 01:05:00 Jul 1 2018 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-100471r1_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_CHAIN
key 1
key-string xxxxxxx
send-lifetime 00:00:00 Jan 1 2018 23:59:59 Mar 31 2018
accept-lifetime 00:00:00 Jan 1 2018 01:05:00 Apr 1 2018
key 2
key-string yyyyyyy
send-lifetime 00:00:00 Apr 1 2018 23:59:59 Jun 30 2018
accept-lifetime 23:55:00 Mar 31 2018 01:05:00 Jul 1 2018

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-107269r1_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_CHAIN SW1(config-keychain)#key 1 SW1(config-keychain-key)#key-string xxxxxx SW1(config-keychain-key)#send-lifetime 00:00:00 Jan 1 2018 23:59:59 Mar 31 2018 SW1(config-keychain-key)#accept-lifetime 00:00:00 Jan 1 2018 01:05:00 Apr 1 2018 SW1(config-keychain-key)#exit SW1(config-keychain)#key 2 SW1(config-keychain-key)#key-string yyyyyyy SW1(config-keychain-key)#send-lifetime 00:00:00 Apr 1 2018 23:59:59 Jun 30 2018 SW1(config-keychain-key)#accept-lifetime 23:55:00 Mar 31 2018 01:05:00 Jul 1 2018 SW1(config-keychain-key)#end

Fix Text (F-107269r1_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_CHAIN
SW1(config-keychain)#key 1
SW1(config-keychain-key)#key-string xxxxxx
SW1(config-keychain-key)#send-lifetime 00:00:00 Jan 1 2018 23:59:59 Mar 31 2018
SW1(config-keychain-key)#accept-lifetime 00:00:00 Jan 1 2018 01:05:00 Apr 1 2018
SW1(config-keychain-key)#exit
SW1(config-keychain)#key 2
SW1(config-keychain-key)#key-string yyyyyyy
SW1(config-keychain-key)#send-lifetime 00:00:00 Apr 1 2018 23:59:59 Jun 30 2018
SW1(config-keychain-key)#accept-lifetime 23:55:00 Mar 31 2018 01:05:00 Jul 1 2018
SW1(config-keychain-key)#end