Device Control Overview
Device Control overview
Device Control allows to an network administrator to protect network by disallowing to use some hardware devices (USB sticks, CD-ROM drives, web-cameras and so on).
When prohibited device is plugged in - the Device Control turns it off to prevent user access.
Device Control is provided with Client Security 9.3x
Installing Device Control
Device Control is installed by default with Client Security 9.30. Default rules doesn't disallow any devices. To use the function the Device Control have to be configured from the Policy Manager.
Device Control configuration
Device Control can be configured from the Policy Manager only. There are no local configuration user interface.
Device control options
|Device Control Enabled||
||Allow to disable Device Control. All rules and options will be ignored if this option has "Disabled" value|
||Specifies the type of alert that is sent when a device is blocked. The administrator will receive the corresponding type of alert. For example, if 'Warning' is selected, the administrator will receive a warning alert. If 'No Alerts' is selected, the administrator will not receive any alerts for blocked devices.|
|Hardware Devices||This table contains the rules for device control. The most specific rule will be used to determine the access level for a device. Devices can be identified by (from specific to general):
Hardware Devices table
||This flag indicates that the rule is in use|
|Display Name||The rule name that is shown to administrators. This name should help administrators to organize rules.|
|Hardware ID||The string that identifies the device (Device ID, Hardware ID, Compatible ID or Class GUID).|
||The access level for the device.|
How Device Control block devices
In Windows every device have a few sets of properties that can be used to identify the device or the class of device.
In the table below the properties are ordered by specificity from most specific to general:
|Device ID||A device has only one device ID that is the most specific ID for a device.|
|Hardware IDs||Device can have multiple hardware IDs. They are also ordered by specificity.|
|Compatible IDs||List of general IDs for all devices of the same kind.|
|Class||A single GUID of device interface class. Every device has one and only one class. This is a registry key under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class where device information are stored. There are list of common classes but some devices generates unique class.|
- Device Control subscribes to the system notification about hardware configuration changes.
- When configuration changed Device Control enumerates all devices.
- For every device device identifiers checked starting from Device ID down to Class GUID.
- If matching rule found Device Control check the Access Level from the rule.
- If rule has Full access and device is blocked - Device Control remove block (enable the device).
- If rule has Blocked access level and device id not blocked - Device Control blocks (disable) the device.
- If access level match the current state of the device then no action is performed.
- When device is blocked for the first time - flyer notification is shown to the current user.
- Policy manager administrator gets the alert every time when device is blocked.
Block access using predefined rules
Device Control is provided with the set of common rules:
- USB Mass Storage Devices
- Wireless devices
NOTE: Some USB Wi-Fi adapters doesn't use the USB\Class_E0 hardware id. To control such devices one should create a custom rule.
- DVD/CD-ROM drives
- Windows CE ActiveSync devices
- Floppy drives
- COM & LPT ports
NOTE: This rule control not a device connected too the COM or LPT port but ports itself.
- Smart Card Readers
- Imaging Devices (cameras and scanners)
- IEEE 1394 Host Bus Controllers
- IrDA Devices
- Bluetooth Devices
To prevent users from use devices administrator should select "Blocked" access level for desired rule.
Adding exceptions (grant access to the specific device)
It is possible to define rules that allows to use some specific device when all other devices of same class will be blocked:
- Get Hardware ID of device that should be allowed. The Hardware ID have to be more specific that ID used to block the device.
- Add new rule in Hardware Devices table with the ID.
- Set "Full access" access level for the new created rule.
- Set Active "Yes" for the new created rule.
Getting Hardware ID for device
There are several ways to get Hardware IDs of device to use it in rules:
- Using Device Control statistics
- Using Windows Device Manager
Getting Hardware ID from statistics
- Open Device Control statistic in the Policy Manager.
- Find an interesting device in Devices table that should be used inrules
- Use one of values from Hardware IDs, Compatible IDs or Device Class columns
Getting Hardware ID from Windows Device Manager
- From Control Panel open Device Manager
- Select an interesting device in the tree
- Open properties dialog
- Go to Details tab
- There are following properties with IDs:
- Hardware IDs
- Compatible IDs
- Device class guid
Device Control statistics
Device control reports about all devices installed on the PC using PM statistics. Device Control Statistics contains following table:
|Device ID||The device ID|
|Device Name||The name of device reported by system|
|Hardware IDs||The comma-separated list of Hardware IDs|
|Compatible IDs||The comma-separated list of Compatible IDs|
|Device class||The Device class guid|
|State||The sate of device reported by Windows:
|Rule||If device was disabled by Device Control this field will contain Hardware Id from rule affected rule|