CVE-2021-38789
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 · uneditedAllwinner R818 SoC Android Q SDK V1.0 is affected by an incorrect access control vulnerability that does not check the caller's permission, in which a third-party app could change system settings.
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 · moderate confidenceThe Allwinner R818 SoC Android Q SDK V1.0 contains an incorrect access control vulnerability where system settings modification functions fail to verify the caller's permissions. This allows any third-party application installed on the device to change system settings without proper authorization, bypassing Android's permission model.
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= 1.0CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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 checksWork through these to decide whether this CVE applies to you.
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Identify the SoC modelCheck the device specifications or use commands like 'cat /proc/cpuinfo' or 'getprop ro.hardware' to confirm the system-on-chip is Allwinner R818Affected if The device is not using the Allwinner R818 SoC
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Verify the SDK versionCheck the Android SDK version via 'getprop ro.build.version.sdk' or check the firmware/build details to confirm it is Android Q (SDK level 29)Affected if The SDK version is not Android Q (SDK 29)
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Confirm SDK is version 1.0Check the SDK-specific build property such as 'getprop ro.build.version.allwinner' or inspect the firmware metadata to verify the SDK version is exactly 1.0Affected if The SDK version is not exactly 1.0
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Test third-party app settings modificationInstall a test application that attempts to modify system settings (such as screen brightness or airplane mode) WITHOUT requesting WRITE_SETTINGS permission and verify if the changes are allowedAffected if Third-party applications can modify system settings without having WRITE_SETTINGS permission granted
A device is affected if it uses the Allwinner R818 SoC with Android Q SDK version 1.0 and allows third-party applications to modify system settings without proper WRITE_SETTINGS permission authorization.
Generated from the published advisory. Verify against your own configuration.
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 dataImplement proper permission checks (such as Android's WRITE_SETTINGS or equivalent) before allowing system settings modifications, validating the calling application's UID and requested permissions against a whitelist of authorized system components.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-38789 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-38789 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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