CVE-2018-14996 [High] | Security Vulnerability in F5 Firmware

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.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.05%	0.52%	+0.46%
2	2023-03-07	1.36%	0.05%	-1.31%
3	2022-02-04	—	1.36%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.05%

0.52%

+0.46%

2023-03-07

1.36%

0.05%

-1.31%

2022-02-04

—

1.36%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.8	3.0	HIGH	`CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	[email protected]
7.2	2.0	HIGH	`AV:L/AC:L/Au:N/C:C/I:C/A:C` Click to expand Access vector (AV:L) Requires local access to the target system. Access complexity (AC:L) Exploitation conditions are straightforward and predictable. Authentication (AU:N) No authentication is required. Confidentiality impact (C:C) Complete confidentiality impact. Integrity impact (I:C) Complete integrity impact. Availability impact (A:C) Complete availability impact.	3.9	10.0	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.8

3.0

HIGH

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

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

[email protected]

7.2

2.0

HIGH

AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand

Access vector (AV:L): Requires local access to the target system.
Access complexity (AC:L): Exploitation conditions are straightforward and predictable.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:C): Complete confidentiality impact.
Integrity impact (I:C): Complete integrity impact.
Availability impact (A:C): Complete availability impact.

3.9

10.0

[email protected]

Affected software / configurations for CVE-2018-14996

Vendor	Product	Version	Raw CPE
oppo	f5_firmware	—	cpe:2.3:o:oppo:f5_firmware:-:::::::*

References for CVE-2018-14996

URL	Tags
https://www.kryptowire.com	Third Party Advisory
https://www.kryptowire.com/portal/android-firmware-defcon-2018/	Third Party Advisory
https://www.kryptowire.com/portal/wp-content/uploads/2018/12/DEFCON-26-Johnson-and-Stavrou-Vulnerable-Out-of-the-Box-An-Eval-of-Android-Carrier-Devices-WP-Updated.pdf	Technical Description Third Party Advisory

URL

CVE-2018-14996

Exploit prediction scoring system (EPSS) score for CVE-2018-14996

Common vulnerability scoring system (CVSS) metrics for CVE-2018-14996

Weakness enumeration for CVE-2018-14996

Affected software / configurations for CVE-2018-14996

References for CVE-2018-14996