Title

Apple iOS/iPadOS 15 must implement the management setting: enable USB Restricted Mode. (Cat II impact)

Discussion

The USB lightning port on an iOS device can be used to access data on the device. The required settings ensure the Apple device password is entered before a previously trusted USB accessory can connect to the device. SFR ID: FMT_SMF_EXT.1.1 #47

Check Content

This is a supervised-only control. If the iPhone or iPad being reviewed is not supervised by the MDM, this control is automatically a finding. If the iPhone or iPad being reviewed is supervised by the MDM, review configuration settings to confirm "Allow USB Restricted Mode" is enabled. This check procedure is performed on both the device management tool and the iPhone and iPad device. Note: If an organization has multiple configuration profiles, the check procedure must be performed on the relevant configuration profiles applicable to the scope of the review. In the iOS management tool, verify "Allow USB Restricted Mode" is checked. On the iPhone/iPad device: 1. Open the Settings app. 2. Tap "General". 3. Tap "Profiles & Device Management" or "Profiles". 4. Tap the Configuration Profile from the iOS management tool containing the restrictions policy. 5. Tap "Restrictions". 6. Verify "Allow USB Restricted Mode" is listed. If "Allow USB Restricted Mode" is not enabled in both the management tool and on the Apple device, this is a finding. Note: "Allow USB Restricted Mode" may be called "Allow USB accessories while device is locked" in some MDM consoles. The required logic is to disable USB accessory connections when the device is locked.

Fix Text

Install a configuration profile to disable "Allow USB Restricted Mode" in the management tool. This a supervised-only control. Note: This control is called "Allow USB accessories while device is locked" in Apple Configurator, and the control logic is opposite to what is listed here. Ensure the MDM policy rule is set correctly (to disable USB accessory connections when the device is locked).

Additional Identifiers

Rule ID: SV-250964r801983_rule

Vulnerability ID: V-250964

Group Title: PP-MDF-990000

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.