Title

Apple iOS must disable voice-activated assistant functionality when the device is locked (Siri). (Cat II impact)

Discussion

On iOS devices, users can access the device's contact database or calendar to obtain phone numbers and other information using a human voice even when the mobile device is locked. Often this information is personally identifiable information (PII), which is considered sensitive. It could also be used by an adversary to profile the user or engage in social engineering to obtain further information from other unsuspecting users. Disabling access to the contact database and calendar in these situations mitigates the risk of this attack. The DAA may waive this requirement with written notice if the operational environment requires this capability.

Check Content

This check procedure is performed on both the iOS Over-the-Air management tool and the iOS device. Note: If an organization has multiple configuration profiles, then the check procedure must be performed on the relevant configuration profiles applicable to the scope of the review. In the iOS Over-the-Air management tool, verify "Allow Siri while device is locked" is unchecked. For example, in Mobile Iron Admin Portal: 1. Ask the MDM administrator to display the "POLICIES & CONFIGS". 2. Click or tap on the word "Configurations". 3. Click or tap the configuration name. 4. Expand "Details" under "App Setting Details". 5. Verify "Allow Siri while device is locked" is set to "false". Alternatively, verify the text "<key>allowAssistant</key><false/>" appears in the configuration profile (.mobileconfig file). On the iOS device: 1. Hold down the home button on a locked iOS device for 5 seconds. 2. Verify that Siri does not activate. If "Allow Siri while device is locked" is checked in the iOS Over-the-Air management tool, "<key>allowAssistant</key><true/>" appears in the configuration profile, or Siri activates on a locked iOS device, this is a finding.

Fix Text

Configure Apple iOS to disable access to the device's contact database when the device is locked. In the iOS Over-the-Air management tool, uncheck "Allow Siri while device is locked". For example, in Mobile Iron Admin Portal, edit the configuration and deselect the "Allow Siri while device is locked".

Additional Identifiers

Rule ID:

Vulnerability ID: V-43212

Group Title:

Expert Comments

CCIs tied to check.

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