SSH Credentials

Use SSH credentials for host-based checks on Unix systems and supported network devices. Tenable Security Center uses these credentials to obtain local information from remote Unix systems for patch auditing or compliance checks. Tenable Security Center uses Secure Shell (SSH) protocol version 2 based programs (e.g., OpenSSH, Solaris SSH, etc.) for host-based checks.

Tenable Security Center encrypts the data using the AES-256-CBC algorithm to protect it from being viewed by sniffer programs.

Note: Non-privileged users with local access on Linux systems can determine basic security issues, such as patch levels or entries in the /etc/passwd file. For more comprehensive information, such as system configuration data or file permissions across the entire system, an account with root privileges is required.

Note: You can add up to 1000 SSH credentials in a single scan. For best performance, Tenable recommends adding no more than 10 SSH credentials per scan.

Configure the following options for SSH credentials, including options specific for your authentication method:

General Option	Description
Name	(Required) A name for the credential.
Description	A description for the credential.
Tag	A tag for the credential. For more information, see Tags.

Arcon Options

The following table describes the additional options to configure when using Arcon as the authentication method for SSH credentials.

Option	Description
Arcon Host	(Required) The Arcon IP address or DNS address. Note: If your Arcon installation is in a subdirectory, you must include the subdirectory path. For example, type IP address or hostname/subdirectory path.
Arcon Port	(Required) The port on which Arcon listens. By default, Tenable Security Center uses port 444.
API User	(Required) The API user provided by Arcon.
API Key	(Required) The API key provided by Arcon.
Authentication URL	(Required) The URL Tenable Security Center uses to access Arcon.
Password Engine URL	(Required) The URL Tenable Security Center uses to access the passwords in Arcon.
Username	(Required) The username to log in to the hosts you want to scan.
Arcon Target Type	(Optional) The name of the target type. Depending on the Arcon PAM version you are using and the system type the SSH credential has been created with, this is set to linux by default. Refer to the Arcon PAM Specifications document (provided by Arcon) for target type/system type mapping for the correct target type value.
Checkout Duration	(Required) The length of time, in hours, that you want to keep credentials checked out in Arcon. Configure the Checkout Duration to exceed the typical duration of your Tenable Security Center scans. If a password from a previous scan is still checked out when a new scan begins, the new scan fails. Tip: Configure the password change interval in Arcon so that password changes do not disrupt your Tenable Security Center scans. If Arcon changes a password during a scan, the scan fails.
Use SSL	When enabled, Tenable Security Center uses SSL through IIS for secure communications. You must configure SSL through IIS in Arcon before enabling this option.
Verify SSL Certificate	When enabled, Tenable Security Center validates the SSL certificate. You must configure SSL through IIS in Arcon before enabling this option.
Privilege Escalation	The privilege escalation method you want to use to increase users' privileges after initial authentication. Your Privilege Escalation selection determines the specific options you must configure. For more information, see Privilege Escalation.
Targets to Prioritize Credentials	Specify IPs or CIDR blocks on which this credential is attempted before any other credential. To specify multiple IPs or CIDR blocks, use a comma or space-separated list. Using this setting can decrease scan times by prioritizing a credential that you know works against your selected targets. For example, if your scan specifies 100 credentials, and the successful credential is the 59th credential out of 100, the first 58 credentials have to fail before the 59th credential succeeds. If you use Targets To Prioritize Credentials, you configure the scan to use the successful credential first, which allows the scan to access the target faster.

BeyondTrust Options

The following table describes the additional options to configure when using BeyondTrust as the authentication method for SSH credentials.

Option	Description
Username	The username to log in to the hosts you want to scan.
BeyondTrust Host	The BeyondTrust IP address or DNS address.
BeyondTrust Port	The port BeyondTrust is listening on.
BeyondTrust API User	The API user provided by BeyondTrust.
BeyondTrust API Key	The API key provided by BeyondTrust.
Checkout Duration	The length of time, in minutes, that you want to keep credentials checked out in BeyondTrust. Configure the Checkout duration to exceed the typical duration of your Tenable Security Center scans. If a password from a previous scan is still checked out when a new scan begins, the new scan fails. Tip: Configure the password change interval in BeyondTrust so that password changes do not disrupt your Tenable Security Center scans. If BeyondTrust changes a password during a scan, the scan fails.
Use SSL	If enabled, Tenable Security Center uses SSL through IIS for secure communications. You must configure SSL through IIS in BeyondTrust before enabling this option.
Verify SSL Certificate	If enabled, Tenable Security Center validates the SSL certificate. You must configure SSL through IIS in BeyondTrust before enabling this option.
Use Private Key	If enabled, Tenable Security Center uses key-based authentication for SSH connections instead of password authentication.
Use Privilege Escalations	If enabled, Tenable Security Center uses BeyondTrust for privilege escalation.

Centrify Options

The following table describes the additional options to configure when using Centrify as the authentication method for SSH credentials.

Option	Description
Centrify Host	(Required) The Centrify IP address or DNS address. Note: If your Centrify installation is in a subdirectory, you must include the subdirectory path. For example, type IP address or hostname/subdirectory path.
Centrify Port	(Required) The port on which Centrify listens. By default, Tenable Security Center uses port 443.
API User	(Required) The API user provided by Centrify.
API Key	(Required) The API key provided by Centrify.
Tenant	(Required) The Centrify tenant associated with the API. By default, Tenable Security Center uses centrify.
Authentication URL	(Required) The URL Tenable Security Center uses to access Centrify. By default, Tenable Security Center uses /Security.
Password Query URL	(Required) The URL Tenable Security Center uses to query the passwords in Centrify. By default, Tenable Security Center uses /RedRock.
Password Engine URL	(Required) The URL Tenable Security Center uses to access the passwords in Centrify. By default, Tenable Security Center uses /ServerManage.
Username	(Required) The username to log in to the hosts you want to scan.
Checkout Duration	(Required) The length of time, in minutes, that you want to keep credentials checked out in Centrify. Configure the Checkout Duration to exceed the typical duration of your Tenable Security Center scans so that password changes do not disrupt your Tenable Security Center scans. If Centrify changes a password during a scan, the scan fails. If a password from a previous scan is still checked out when a new scan begins, the new scan fails.
Use SSL	When enabled, Tenable Security Center uses SSL through IIS for secure communications. You must configure SSL through IIS in Centrify before enabling this option.
Verify SSL Certificate	When enabled, Tenable Security Center validates the SSL certificate. You must configure SSL through IIS in Centrify before enabling this option.

Certificate Options

The following table describes the additional options to configure when using Certificate as the authentication method for SSH credentials.

Option	Description
Username	(Required) The username for a user on the host system.
User Certificate	(Required) The RSA or DSA OpenSSH certificate file for the user.
Private Key	(Required) The RSA or DSA OpenSSH private key file for the user.
Passphrase	The passphrase for the private key, if required.
Privilege Escalation	The privilege escalation method you want to use to increase users' privileges after initial authentication. Your Privilege Escalation selection determines the specific options you must configure. For more information, see Privilege Escalation.

CyberArk Vault Options

The following table describes the additional options to configure when using CyberArk Vault as the authentication method for SSH credentials.

Option	Description	Required
CyberArk Elevate Privileges With	The privilege escalation method you want to use to increase users' privileges after initial authentication. Your CyberArk Elevate Privileges With selection determines the specific options you must configure. For more information, see Privilege Escalation.	no
CyberArk Host	The IP address or FQDN name for the CyberArk AIM Web Service.	yes
Port	The port on which the CyberArk API communicates. By default, Tenable uses 443.	yes
AppID	The Application ID associated with the CyberArk API connection.	yes
Client Certificate	The file that contains the PEM certificate used to communicate with the CyberArk host.	no
Client Certificate Private Key	The file that contains the PEM private key for the client certificate.	yes, if private key is applied
Client Certificate Private Key Passphrase	The passphrase for the private key, if required.	yes, if private key is applied
Kerberos Target Authentication	If enabled, Kerberos authentication is used to log in to the specified Linux or Unix target.	no
Key Distribution Center (KDC)	(Required if Kerberos Target Authentication is enabled) This host supplies the session tickets for the user.	yes
KDC Port	(Required if Kerberos Target Authentication is enabled.) The port on which the Kerberos authentication API communicates. By default, Tenable uses 88.	yes
KDC Transport	(Required if Kerberos Target Authentication is enabled.) The KDC uses TCP by default in Linux implementations. For UDP, change this option. If you need to change the KDC Transport value, you may also need to change the port as the KDC UDP uses either port 88 or 750 by default, depending on the implementation.	yes
Realm	(Required if Kerberos Target Authentication is enabled) The Realm is the authentication domain, usually noted as the domain name of the target (for example, example.com). By default, Tenable Security Center uses 443.	yes
Get credential by	The method with which your CyberArk API credentials are retrieved. Can be Address, Identifier, Parameters, or Username. Note: For more information about the Parameters option, refer to the Parameters Options table. Note: The frequency of queries for Username is one query per target. The frequency of queries for Identifier is one query per chunk. This feature requires all targets have the same identifier. Note: The Username option also adds the Address parameter of the API query and assigns the target IP of the resolved host to the Address parameter. This may lead to failure to fetch credentials if the CyberArk Account Details Address field contains a value other than the target IP address.	yes
Username	(If Get credential by is set to Username) The username of the CyberArk user to request a password from.	no
Safe	The CyberArk safe the credential should be retrieved from.	no
Address	The option should only be used if the Address value is unique to a single CyberArk account credential.	no
Account Name	(If Get credential by is Identifier) The unique account name or identifier assigned to the CyberArk API credential.	no
Use SSL	If enabled, the scanner uses SSL through IIS for secure communications. Enable this option if CyberArk is configured to support SSL through IIS.	no
Verify SSL Certificate	If enabled, the scanner validates the SSL certificate. Enable this option if CyberArk is configured to support SSL through IIS and you want to validate the certificate.	no
Targets to Prioritize Credentials	Specify IPs or CIDR blocks on which this credential is attempted before any other credential. To specify multiple IPs or CIDR blocks, use a comma or space-separated list. Using this setting can decrease scan times by prioritizing a credential that you know works against your selected targets. For example, if your scan specifies 100 credentials, and the successful credential is the 59th credential out of 100, the first 58 credentials have to fail before the 59th credential succeeds. If you use Targets To Prioritize Credentials, you configure the scan to use the successful credential first, which allows the scan to access the target faster.	no

CyberArk Vault (Legacy) Options

The following table describes the additional options to configure when using CyberArk Vault (Legacy) as the authentication method for SSH credentials.

Option	Description
Username	(Required) The username for the target system.
CyberArk elevate privileges with	The privilege escalation method you want to use to increase users' privileges after initial authentication. Your CyberArk elevate privileges with selection determines the specific options you must configure. For more information, see Privilege Escalation.
Central Credential Provider URL Host	(Required) The CyberArk Central Credential Provider IP/DNS address.
Central Credential Provider URL Port	(Required) The port the CyberArk Central Credential Provider is listening on.
CyberArk Address	The domain for the CyberArk account. You must configure SSL through IIS in CyberArk Central Credential Provider before configuring this option.
Vault Username	The username for the vault, if the CyberArk Central Credential Provider is configured for basic authentication.
Vault Password	The password for the vault, if the CyberArk Central Credential Provider is configured for basic authentication.
Safe	(Required) The safe on the CyberArk Central Credential Provider server that contains the credentials you want to retrieve.
CyberArk Client Certificate	The file that contains the PEM certificate used to communicate with the CyberArk host.
CyberArk Client Certificate Private Key	The file that contains the PEM private key for the client certificate.
CyberArk Client Certificate Private Key Passphrase	The passphrase for the private key, if required.
AppID	(Required) The AppID with CyberArk Central Credential Provider permissions to retrieve the target password.
Folder	(Required) The folder on the CyberArk Central Credential Provider server that contains the credentials you want to retrieve.
PolicyID	The PolicyID assigned to the credentials you want to retrieve.
Vault Use SSL	When enabled, Tenable Security Center uses SSL through IIS for secure communications. You must configure SSL through IIS in CyberArk Central Credential Provider before enabling this option.
Vault Verify SSL	When enabled, Tenable Security Center validates the SSL certificate. You must configure SSL through IIS in CyberArk Central Credential Provider before enabling this option.
CyberArk Escalation Account Details Name	The unique name of the credential you want to retrieve from CyberArk.
CyberArk AIM Service URL	The URL for the CyberArk AIM web service. By default, Tenable Security Center uses /AIMWebservice/v1.1/AIM.asmx.

Hashicorp Vault Options

The following table describes the additional options to configure when using Hashicorp Vault as the authentication method for SSH credentials.

Option	Default Value	Required
Hashicorp Host	The Hashicorp Vault IP address or DNS address. Note: If your Hashicorp Vault installation is in a subdirectory, you must include the subdirectory path. For example, type IP address or hostname/subdirectory path.	yes
Hashicorp Port	The port on which Hashicorp Vault listens.	yes
Authentication Type	Specifies the authentication type for connecting to the instance: App Role or Certificates. If you select Certificates, additional options for Hashicorp Client Certificate (Required) and Hashicorp Client Certificate Private Key (Required) appear. Select the appropriate files for the client certificate and private key.	yes
Role ID	The GUID provided by Hashicorp Vault when you configured your App Role.	yes
Role Secret ID	The GUID generated by Hashicorp Vault when you configured your App Role.	yes
Authentication URL	The path/subdirectory to the authentication endpoint. This is not the full URL. For example: /v1/auth/approle/login	yes
Namespace	The name of a specified team in a multi-team environment.	no
Hashicorp Vault Type	The type of Hashicorp Vault secrets engine: KV1 — Key/Value Secrets Engine Version 1 KV2 — Key/Value Secrets Engine Version 2 AD — Active Directory	yes
KV1 Engine URL KV2 Engine URL AD Engine URL	The URL Tenable Security Center uses to access the Hashicorp Vault secrets engine. Example: /v1/path_to_secret. No trailing /	yes
Username Source	(Appears when Hashicorp Vault Type is KV1 or KV2) Specifies if the username is input manually or pulled from Hashicorp Vault.	yes
Username Key	(Appears when Hashicorp Vault Type is KV1 or KV2) The name in Hashicorp Vault that usernames are stored under.	yes
Password Key	(Appears when Hashicorp Vault Type is KV1 or KV2) The key in Hashicorp Vault that passwords are stored under.	yes
Secret Name	The key secret you want to retrieve values for.	yes
Use SSL	When enabled, Tenable Security Center uses SSL for secure communications. You must configure SSL in Hashicorp Vault before enabling this option.	no
Verify SSL	When enabled, Tenable Security Center validates the SSL certificate. You must configure SSL in Hashicorp Vault before enabling this option.	no
Targets to Prioritize Credentials	Specify IPs or CIDR blocks on which this credential is attempted before any other credential. To specify multiple IPs or CIDR blocks, use a comma or space-separated list. Using this setting can decrease scan times by prioritizing a credential that you know works against your selected targets. For example, if your scan specifies 100 credentials, and the successful credential is the 59th credential out of 100, the first 58 credentials have to fail before the 59th credential succeeds. If you use Targets To Prioritize Credentials, you configure the scan to use the successful credential first, which allows the scan to access the target faster.	no

Kerberos Options

The following table describes the additional options to configure when using Kerberos as the authentication method for SSH credentials.

Option	Description
Username	(Required) The username for a user on the target system.
Password	(Required) The password associated with the username you provided.
KDC Host	(Required) The host supplying the session tickets.
KDC Port	(Required) The port you want to use for the KDC connection. By default, Tenable Security Center uses port 88.
KDC Transport	(Required) The method you want to use to connect to the KDC server. Note: If you select UDP, you may need to edit the KDC Port. The KDC UDP protocol uses either port 88 or port 750.
Realm	(Required) The authentication domain, typically the domain name of the target (e.g., example.com).
Privilege Escalation	The privilege escalation method you want to use to increase users' privileges after initial authentication. Your Privilege Escalation selection determines the specific options you must configure. For more information, see Privilege Escalation.

Lieberman Options

The following table describes the additional options to configure when using Lieberman as the authentication method for SSH credentials.

Option	Description
Username	The username for a user on the database.
Lieberman Host	The Lieberman IP address or DNS address. Note: If your Lieberman installation is in a subdirectory, you must include the subdirectory path. For example, type IP address or hostname/subdirectory path.
Lieberman Port	The port Lieberman is listening on.
Lieberman User	The username for the Lieberman explicit user you want Tenable Security Center to use for authentication to the Lieberman Rapid Enterprise Defense (RED) API.
Lieberman Password	The password for the Lieberman explicit user.
Use SSL	When enabled, Tenable Security Centeruses SSL through IIS for secure communications. You must configure SSL through IIS in Lieberman before enabling this option.
Verify SSL Certificate	When enabled, Tenable Security Center validates the SSL certificate. You must configure SSL through IIS in Lieberman before enabling this option.
System Name	The name for the database credentials in Lieberman.

Password Options

The most effective credentialed scans are those with root privileges (enable privileges, for Cisco IOS). Since many sites do not permit a remote login as root for security reasons, a Nessus user account can invoke a variety of privilege escalation options including: su, sudo, su+sudo, DirectAuthorize (dzdo), PowerBroker (pbrun), k5login, and Cisco Enable.

The following table describes the additional options to configure when using Password as the authentication method for SSH credentials.

Option	Description
Username	(Required) The username for a user on the target system.
Password	(Required) The password associated with the username you provided.
Privilege Escalation	The privilege escalation method you want to use to increase users' privileges after initial authentication. Your Privilege Escalation selection determines the specific options you must configure. For more information, see Privilege Escalation.

Public Key Options

The following table describes the additional options to configure when using Public Key as the authentication method for SSH credentials.

Option	Description
Username	(Required) The username for a user on the host system.
Private Key	(Required) The RSA or DSA OpenSSH key file for the user.
Passphrase	The passphrase for the private key, if required.
Privilege Escalation	The privilege escalation method you want to use to increase users' privileges after initial authentication. Your Privilege Escalation selection determines the specific options you must configure. For more information, see Privilege Escalation.

Thycotic Secret Server Options

The following table describes the additional options to configure when using Thycotic Secret Server as the authentication method for SSH credentials.

Option	Description
Username	(Required) The username for a user on the target system.
Thycotic elevate privileges with	The privilege escalation method you want to use to increase users' privileges after initial authentication. Your selection for this setting determines the specific options you must configure. For more information, see Privilege Escalation.
Thycotic Secret Name	The Secret Name value on the Thycotic server.
Thycotic Secret Server URL	(Required) The value you want Tenable Security Center to use when setting the transfer method, target, and target directory for the scanner. Find the value on the Thycotic server, in Admin > Configuration > Application Settings > Secret Server URL. For example, if you type https://pw.mydomain.com/SecretServer, Tenable Security Center determines it is an SSL connection, that pw.mydomain.com is the target address, and that /SecretServer is the root directory.
Thycotic Login Name	(Required) The username for a user on the Thycotic server.
Thycotic Password	(Required) The password associated with the Thycotic Login Name you provided.
Thycotic Organization	In cloud instances of Thycotic, the value that identifies the organization you want Tenable Security Center to target.
Thycotic Domain	The domain, if set for the Thycotic server.
Verify SSL Certificate	If enabled, Tenable Security Center verifies the SSL Certificate on the Thycotic server. For more information about using self-signed certificates, see the Nessus custom_CA.inc documentation.
Use Private Key	If enabled, Tenable Security Center uses key-based authentication for SSH connections instead of password authentication.