Controls/EDCA-IAC-024.json

{
  "id": "EDCA-IAC-024",
  "title": "Mobile device mailbox policy locks after 15 minutes of inactivity",
  "description": "The MaxInactivityTimeLock property on the default mobile device mailbox policy MUST be 15 minutes or less. Locking the device after a period of inactivity reduces the risk of unauthorised access if a device is left unattended. The CIS benchmark requires a maximum inactivity lock time of 15 minutes.",
  "verify": true,
  "subject": "Organization",
  "category": "Identity and Access Control",
  "severity": "Medium",
  "severityWeight": 5,
  "frameworks": [
    "Best Practice",
    "CIS"
  ],
  "references": [
    {
      "name": "CIS 3.11 (L1): Ensure Time without user input before password must be re-entered is set to 15",
      "url": "https://www.cisecurity.org/benchmark/microsoft_exchange_server"
    },
    {
      "name": "Mobile device mailbox policies in Exchange Server",
      "url": "https://learn.microsoft.com/exchange/clients/exchange-activesync/mobile-device-mailbox-policies"
    }
  ],
  "remediation": {
    "automatable": true,
    "description": "Set the inactivity lock timeout to 15 minutes or less in the default mobile device mailbox policy.",
    "scriptTemplate": "# Set the inactivity lock to 15 minutes in the default mobile device mailbox policy.\nSet-MobileDeviceMailboxPolicy -Identity Default -MaxInactivityTimeLock 00:15:00"
  },
  "considerations": "A shorter inactivity timeout provides more security but may be inconvenient for users. A 15-minute limit is broadly accepted as a good balance. Consider shorter timeouts for high-security environments.",
  "roles": [
    "Mailbox"
  ]
}