Why bluetooth device is always discoverable?

[tango4567]

1. Bluetooth is always discoverable when enabled and you can't change that setting.
2. What are the disadvantages to keep Bluetooth always discoverable?
3. Is it possible to retrieve data from discoverable devices without user permission?

[tango4567]

1. Yes, most of the latest devices don't have these settings and this is a huge security flaw.
2. My personal experience whenever I went to a crowded place I received several attempts to file sharing and pairing requests.
3. Yes this 100% possible to retrieve data from discoverable devices without user permission.

In latest versions of Android, iOS, Linux and Windows Bluetooth is always discoverable. There is no such setting available to make it undiscoverable. This a major security issue then is started digging and more digging, then I found some shocking reports which says, "First time, on September 12, 2017, a security firm Armis reported The BlueBorne security vulnerabilities."

What is BlueBorne? (Explained by Armis Lab)

BlueBorne is an attack vector by which hackers can leverage Bluetooth connections to penetrate and take complete control over targeted devices. BlueBorne affects ordinary computers, mobile phones, and the expanding realm of IoT devices. The attack does not require the targeted device to be paired to the attacker’s device or even to be set on discoverable mode. Armis Labs has identified eight zero-day vulnerabilities so far, which indicate the existence and potential of the attack vector. Armis believes many more vulnerabilities await discovery in the various platforms using Bluetooth. These vulnerabilities are fully operational and can be successfully exploited, as demonstrated in our research. The BlueBorne attack vector can be used to conduct a large range of offences, including remote code execution as well as Man-in-The-Middle attacks.

After getting reported BlueBorne, several IT companies revealed security guidelines in which few of them are below

1. Google
2. Microsoft

How BlueBorne works? (Explained by Armis Lab)

1. Working of BlueBorne
2. Live Demo on Android

#Python is the most powerful language.
Note: Intention behind this post is to general awareness.
Remark: This is a small research which highlights the major security threats.