The Oppo F5 Android device with a build fingerprint of OPPO/CPH1723/CPH1723:7.1.1/N6F26Q/1513597833:user/release-keys contains a pre-install
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.
- Published
- Apr 25, 2019
- Updated
- Jun 16, 2026
- EPSS
- 0.5% · 42th percentile
- CWE
- —
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
Affected systems
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- www.kryptowire.com
- www.kryptowire.com/portal/android-firmware-defcon-2018/
- 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
Vendor advisories and official records. Exploit/PoC links are deliberately left out.