dbcve.org
F5 FirmwareOperating system · Oppo

CVE-2018-14996

HIGH · 7.8 CVSS v3.0 Published 2019-04-25
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The Oppo F5 Android device with a build fingerprint of OPPO/CPH1723/CPH1723:7.1.1/N6F26Q/1513597833:user/release-keys contains a pre-installed platform app with a package name of com.dropboxchmod (versionCode=1, versionName=1.0) that contains an exported service named com.dropboxchmod.DropboxChmodService that allows any app co-located on the device to supply arbitrary commands to be executed as the system user. This app cannot be disabled by the user and the attack can be performed by a zero-permission app. Executing commands as system user can allow a third-party app to video record the user's screen, factory reset the device, obtain the user's notifications, read the logcat logs, inject events in the Graphical User Interface (GUI), and obtains the user's text messages, and more. This vulnerability can also be used to secretly record audio of the user without their awareness on the Oppo F5 device. The pre-installed com.oppo.engineermode app (versionCode=25, versionName=V1.01) has an exported activity that can be started to initiate a recording and quickly dismissed. The activity can be started in a way that the user will not be able to see the app in the recent apps list. The resulting audio amr file can be copied from a location on internal storage using the arbitrary command execution as system user vulnerability. Executing commands as system user can allow a third-party app to factory reset the device, obtain the user's notifications, read the logcat logs, inject events in the Graphical User Interface (GUI), change the default Input Method Editor (IME) (e.g., keyboard) with one contained within the attacking app that contains keylogging functionality, obtain the user's text messages, and more.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A pre-installed platform app (com.dropboxchmod) on the Oppo F5 contains an exported service that allows any local app to execute arbitrary commands as the system user with root-level privileges. This zero-permission exploit enables screen recording, factory reset, notification theft, SMS exfiltration, logcat access, GUI injection, and covert audio recording via a companion engineer mode app.

MitigationThis is a firmware-level vulnerability requiring an OEM patch from Oppo - users cannot remediate independently. Organizations should advise affected users to avoid installing untrusted applications and monitor for vendor firmware updates.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
F5 FirmwareOperating system
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify device model
    Check device settings or use 'getprop ro.product.model' via ADB to confirm the device is an Oppo F5
    Affected if Device model is Oppo F5 - this is the only affected product per the CVE
  2. Check for vulnerable package
    Use 'pm list packages' via ADB or inspect installed apps to verify if com.dropboxchmod is present on the device
    Affected if The com.dropboxchmod package is installed - this is the vulnerable pre-installed app containing the exported service
  3. Verify service is exported
    Use 'dumpsys package com.dropboxchmod' via ADB to examine the app's manifest and confirm the service has android:exported="true"
    Affected if The exported service is enabled and accessible - the vulnerability requires the service to be exported (android:exported not set to false)
  4. Test service accessibility
    Attempt to bind to the exported service from another app or use 'appops' to check if any app can invoke the service without permissions
    Affected if The service accepts requests from other apps without requiring any permissions - this confirms the zero-permission exploit path exists

User is affected if they use an Oppo F5 device with the com.dropboxchmod package present and its exported service is accessible, as this allows any local app to execute root-level commands.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

This is a firmware-level vulnerability requiring an OEM patch from Oppo - users cannot remediate independently. Organizations should advise affected users to avoid installing untrusted applications and monitor for vendor firmware updates.

Fix this in F5 Firmware Scoped from the published advisory
  • Consultation8.0 h
  • Review / QA4.0 h
12.0 hours of engineering $2,320
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-14996 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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