The Cisco ACI must be configured to enforce the limit of three consecutive invalid logon attempts, after which time it must block any login attempt for 15 minutes.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-271919	SRG-APP-000065-NDM-000214	CACI-ND-000004	SV-271919r1168355_rule	2025-12-11	1

Description
By limiting the number of failed login attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. For Cisco ACI, when a user is in a locked-out state, the lockout is enforced in all nodes that are part of the fabric, including controllers and switches.

ℹ️ Check
1. On the GUI menu bar, choose Admin >> AAA. 2. In the Navigation pane, choose "Security". 3. In the Work pane, choose the Default Settings >> Policy tab. 4. Under Properties, verify the fields as follows: - For "Lockout User after multiple failed login attempts", choose "Enable". - For "Number of failed attempts before user is locked out", enter "3". - For "Time period in which consecutive attempts were failed (m)", enter "15" or an organization-defined value. - For "Duration of lockout (m)", enter "15". If the Cisco ACI fabric is not configured to enforce the limit of three consecutive invalid logon attempts and lock out users for 15 minutes, this is a finding.

ℹ️ Check

1. On the GUI menu bar, choose Admin >> AAA. 2. In the Navigation pane, choose "Security". 3. In the Work pane, choose the Default Settings >> Policy tab. 4. Under Properties, verify the fields as follows: - For "Lockout User after multiple failed login attempts", choose "Enable". - For "Number of failed attempts before user is locked out", enter "3". - For "Time period in which consecutive attempts were failed (m)", enter "15" or an organization-defined value. - For "Duration of lockout (m)", enter "15". If the Cisco ACI fabric is not configured to enforce the limit of three consecutive invalid logon attempts and lock out users for 15 minutes, this is a finding.

✔️ Fix
1. On the GUI menu bar, choose Admin >> AAA. 2. In the Navigation pane, choose "Security". 3. In the Work pane, choose Default Settings >> Edit 4. Under Properties, complete the fields as follows: - For "Lockout User after multiple failed login attempts", choose "Enable". - For "Number of failed attempts before user is locked out", enter "3". - For "Time period in which consecutive attempts were failed (m)", enter "15" (or an organization-defined value). - For "Duration of lockout (m)", enter "15". 5. Click "Submit".

✔️ Fix

1. On the GUI menu bar, choose Admin >> AAA. 2. In the Navigation pane, choose "Security". 3. In the Work pane, choose Default Settings >> Edit 4. Under Properties, complete the fields as follows: - For "Lockout User after multiple failed login attempts", choose "Enable". - For "Number of failed attempts before user is locked out", enter "3". - For "Time period in which consecutive attempts were failed (m)", enter "15" (or an organization-defined value). - For "Duration of lockout (m)", enter "15". 5. Click "Submit".