Yes—but only in a specific historical sense. In November 2017, NowSecure verified an EngineerMode-based method for obtaining root privileges for ADB commands on two OnePlus phones without first unlocking their bootloaders. That finding does not show that every OnePlus phone, or any current OxygenOS version, can be rooted this way.
What did the EngineerMode finding show?
NowSecure reported that it verified the method on a OnePlus 3 running OxygenOS 4.5.1, build ONEPLUS A3003_16_171012, and a OnePlus 5 running OxygenOS 4.5.14, build ONEPLUSA5000_23_171031. The report was published November 14, 2017. Those device and build details define the demonstrated scope; they are not evidence that all OnePlus models were affected.
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The method used a diagnostic activity in the preinstalled EngineerMode app, invoked through ADB. Android Authority reported that the phone had to be physically connected to a computer running ADB. This was a local-access finding, not evidence of a remote attack. The report should not be treated as a current how-to or as proof that the same route works on later software.
Did EngineerMode provide full root access?
OnePlus described EngineerMode as a diagnostic tool for factory production-line testing and after-sales support. The company said the function could enable root for ADB commands, but would not let third-party apps obtain full root privileges. In other words, the reported capability concerned elevated command access through ADB, not unrestricted root access for every app on the phone.
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OnePlus said USB debugging had to be enabled and was off by default. It also said it planned to remove the ADB-root function in an upcoming OTA update. That statement records the company’s announced plan; the sources cited here do not establish when, or across which models, the change shipped. OnePlus’s November 14, 2017 response explains its position.
Does EngineerMode still work on current OnePlus phones?
The available evidence does not establish whether the app or function is present, enabled, or exploitable on current OnePlus phones. The technical verification is from 2017 and covers two specific software builds. OnePlus’s announcement of a planned removal is not, by itself, confirmation of the rollout or patch status for later OxygenOS releases. Do not infer a current vulnerability—or universal remediation—from those records.
Was EngineerMode made by Qualcomm?
Qualcomm later clarified that it did not author the EngineerMode app at issue. A Qualcomm spokesperson told Android Authority that remnants of Qualcomm source code were present and described the app as a modified derivative of an older, similarly named testing app. Early descriptions of the app as Qualcomm-made should therefore be treated as corrected, not as settled authorship. Android Authority’s November 15, 2017 report includes Qualcomm’s clarification.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How does this differ from unlocking a OnePlus bootloader?
| Aspect | EngineerMode finding | Bootloader unlocking |
|---|---|---|
| Mechanism | A diagnostic path invoked through ADB, as reported in 2017. | OnePlus’s separate OEM unlock process, used for purposes such as installing beta software or custom ROMs. |
| Required access or state | The reported setup required USB debugging and a phone physically connected to a computer running ADB. | OnePlus’s guidance calls for enabling OEM unlocking and following its unlock process. |
| Demonstrated scope | NowSecure verified two named devices and builds: OnePlus 3 on OxygenOS 4.5.1 and OnePlus 5 on OxygenOS 4.5.14. | The cited OnePlus page describes its unlock process; it does not establish EngineerMode’s status. |
| Consequences | The 2017 report concerns ADB command privileges; it does not establish the effects of unlocking a bootloader. | OnePlus warns that unsigned custom ROMs may affect device functionality, data, and official software updates. |
Bootloader unlocking is the documented route to modifying a device’s software, while the EngineerMode report described an ADB diagnostic capability on particular historical builds. OnePlus’s current U.S. unlock-token guidance covers its unlock process, not whether EngineerMode remains available on any model.
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