Knox | |
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Developer(s) | Samsung |
Initial release | March 2013 |
Stable release | 3.11 / 15 February 2025 [1] |
Operating system | Android and Tizen |
Website | www |
Samsung Knox is a mobile device management (MDM) and trusted computing framework pre-installed on most Samsung mobile devices, and implements ARM TrustZone in hardware. It allows the management of work devices, such as employee mobile phones, interactive kiosks, and barcode scanners. [2] Like other MBMs, Knox allows organizations to control a device's pre-loaded applications, settings, boot-up animations, home screens, and lock screens. [3]
Knox provides trusted computing and mobile device management (MDM) features. Knox's hardware is based on an implementation of ARM TrustZone, a bootloader ROM, and secure boot (similar to dm-verity and AVB). [4] [5] These trusted computing environments are used to store sensitive data, like cryptographic materials and certificates. [6]
MDM allow businesses to customize their devices for their needs. IT administrators can register new devices, identify a unified endpoint management (UEM) system, define the organizational rules that govern the use of devices, and upgrade device firmware over-the-air. [7] Knox's MDM services are registered and accessed through the web, [8] APIs, or proprietary SDKs. [9]
A few Samsung devices with Knox were approved for US governmental use in 2014, as long as they're not used to store classified data. [10]
Since Android 8, Knox is used to prevent root access to apps even after a successful rooting. [11]
In October 2014, a security researcher discovered that Samsung Knox stores PINs in plain text rather than storing salted and hashed PINs and processing them by obfuscated code. [12]
In May 2016, Israeli researchers Uri Kanonov and Avishai Wool found three vulnerabilities in specific versions of Knox. [13]
Several security flaws were discovered in Knox in 2017 by Project Zero. [14] [15]
Samsung Knox devices use an e-fuse to indicate whether or not an "untrusted" (non-Samsung) boot path has ever been run. The e-Fuse will be set in any of the following cases:
On Galaxy Book devices starting with the Galaxy Book 4, upgrading from one Windows version to another (from 22H2 to 23H2) will not set the e-Fuse, but upgrading to a higher edition (from Home to Pro) will[ citation needed ].
When set, the text "Set warranty bit: <reason>" appears. Once the e-fuse is set, a device can no longer create a Knox Workspace container or access the data previously stored in an existing Knox Workspace. [16] In the United States, this information may be used by Samsung to deny warranty service to devices that have been modified in this manner. [17] Voiding consumer warranties in this manner may be prohibited by the Magnuson–Moss Warranty Act of 1975, at least in cases where the phone's problem is not directly caused by rooting. [18] In addition to voiding the warranty, tripping the e-fuse also prevents some preinstalled apps from running, such as Secure Folder and Samsung Pay.[ citation needed ] For some older versions of Knox, it may be possible to clear the e-fuse by flashing a custom firmware. [19]
The sole purpose of this fuse-burning action is to memorize that a kernel or critical initialization scripts or data that is not under Samsung's control has been put on the device. Once the e-fuse bit is burned, a Samsung KNOX-enabled device can no longer create a KNOX Container or access the data previously stored in an existing KNOX Container.