The OnePlusLogKit app is a system-level application that is capable of capturing a multitude of things from OnePlus smartphones. It can enable adb root which provides privileges for adb commands, but it will not let 3rd-party apps access full root privileges. Qualcomm claims that the EngineerMode app in question was not authored by Qualcomm. Another security researcher has released an Android application to root OnePlus phones quickly by using the backdoor discovered in EngineerMode. The Chinese company has promised to remove the adb Root function in the upcoming OxygenOS update.
Source: https://thehackernews.com/2017/11/oneplus-logkit-app.html