1.4.1 Set 'password' for 'enable secret'

Information

Enable secret password type 5 and enable secret password type 5 must be migrated to the stronger password type 8 or 9. IF a device is upgraded from IOS XE 16.9 or later the type 5 is auto converted to type 9.

Use the enable secret command to provide an additional layer of security over the enable password. The enable secret command provides better security by storing the enable secret password using a nonreversible cryptographic function. The added layer of security encryption provides is useful in environments where the password crosses the network or is stored on a TFTP server.

Rationale:

Requiring the enable secret setting protects privileged EXEC mode. By default, a strong password is not required, a user can just press the Enter key at the Password prompt to start privileged mode. The enable password command causes the device to enforce use of a password to access privileged mode. Enable secrets use a one-way cryptographic hash (MD5). This is preferred to Level 7 enable passwords that use a weak, well-known, and easily reversible encryption algorithm.

Impact:

Default device configuration does not require strong user authentication potentially enabling unfettered access to an attacker that is able to reach the device. Creating a local account with an encrypted password enforces login authentication and provides a fallback authentication mechanism for configuration in a named method list in a situation where centralized authentication, authorization, and accounting services are unavailable. The following is the type of encryption the device will allow as of 15.3: Type 0 this mean the password will not be encrypted when router store it in Run/Start Files command: enable password cisco123

Type 4 this mean the password will be encrypted when router store it in Run/Start Files using SHA-256 which apps like Cain can crack but will take long time command : enable secret 4 Rv4kArhts7yA2xd8BD2YTVbts (notice above is not the password string it self but the hash of the password)

this type is deprecated starting from IOS 15.3(3)

Type 5 this mean the password will be encrypted when router store it in Run/Start Files using MD5 which apps like Cain can crack but will take long time command: enable secret 5 00271A5307542A02D22842 (notice above is not the password string it self but the hash of the password) or enable secret cisco123 (notice above is the password string it self)

Type 7 this mean the password will be encrypted when router store it in Run/Start Files using Vigenere cipher which any website with type7 reverser can crack it in less than one second command : ena password cisco123 service password-encryption

Type 8

this mean the password will be encrypted when router store it in Run/Start Files using PBKDF2-SHA-256

starting from IOS 15.3(3).

Password-Based Key Derivation Function 2 (PBKDF2) with Secure Hash Algorithm, 26-bits (SHA-256) as the hashing algorithm

Example : R1(config)#enable algorithm-type sha256 secret cisco

R1(config)#do sh run | i enable

enable secret 8 $8$mTj4RZG8N9ZDOk$elY/asfm8kD3iDmkBe3hD2r4xcA/0oWS5V3os.O91u.

Example : R1(config)# username yasser algorithm-type sha256 secret cisco

R1# show running-config | inc username

username yasser secret 8 $8$dsYGNam3K1SIJO$7nv/35M/qr6t.dVc7UY9zrJDWRVqncHub1PE9UlMQFs

Type 9

this means the password will be encrypted when router store it in Run/Start Files using scrypt as the hashing algorithm.

starting from IOS 15.3(3)

Example : R1(config)#ena algorithm-type scrypt secret cisco

R1(config)#do sh run | i enable

enable secret 9 $9$WnArItcQHW/uuE$x5WTLbu7PbzGDuv0fSwGKS/KURsy5a3WCQckmJp0MbE

Example : R1(config)# username demo9 algorithm-type scrypt secret cisco

R1# show running-config | inc username

username demo9 secret 9 $9$nhEmQVczB7dqsO$X.HsgL6x1il0RxkOSSvyQYwucySCt7qFm4v7pqCxkKM

Important Notes:

1-If you configure type 8 or type 9 passwords and then downgrade to a release that does not support type 8 and type 9 passwords, you must configure the type 5 passwords before downgrading. If not, you are locked out of the device and a password recovery is required.

2-Starting from IOS 15.3(3)The 4 keyword was deprecated and support for type 8 and type 9 algorithms were added and The warning message for removal of support for the type 4 algorithm was added tect privileged EXEC mode through policies requiring the 'enabling secret' setting, which enforces a one-way cryptographic hash (MD5).

Solution

Configure a strong, enable secret password.

hostname(config)#enable secret 9 {ENABLE_SECRET_PASSWORD}

Default Value:

No enable secret password setup by default

See Also

https://workbench.cisecurity.org/files/3762

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-6(2), 800-53|AC-6(5), CSCv7|4.3

Plugin: Cisco

Control ID: 70a175ea3bfd0243f7d568e1cda3a3ee3ac4b3233acd34469bb27a7142b5320c