The Content Analysis System (CAS) must limit the number of concurrent sessions to a maximum of three for each account type.

Device management includes the ability to control the number of administrators and management sessions that manage a device. Limiting the number of allowed administrators and sessions per administrator based on account type, role, or access type is helpful in limiting risks related to denial of service (DoS) attacks.

This requirement addresses concurrent sessions for administrative accounts and does not address concurrent sessions by a single administrator via multiple administrative accounts. The maximum number of concurrent sessions should be defined based upon mission needs and the operational environment for each system. At a minimum, limits must be set for SSH, HTTPS, account of last resort, and root account sessions.

Verify the number of concurrent user sessions is set to "3" with the following steps:

1. Log on to the SSH CLI with an administrative account. 2. Enter "enable" and provide the password. 3. Enter "show running-config authentication". 4. Review the output for the "max-concurrent-logins" value.

If "max-concurrent-logins" is not set to "3", or the setting is missing, this is a finding.

Configure the maximum concurrent user sessions to "3" with the following steps:

1. Log on to the SSH CLI with an administrative account. 2. Enter "enable" and then enter the password. 3. Enter "configure terminal". 4. Enter "authentication management max-concurrent-logins 3". 5. Enter "exit" to return to the config context, and then enter "exit" again to leave configuration mode.