CVE-2021-39767
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 · uneditedIn miniadb, there is a possible way to get read/write access to recovery system properties due to an insecure default value. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-12LAndroid ID: A-201308542
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 confidenceIn miniadb (Android Debug Bridge component), an insecure default value allows read/write access to recovery system properties. This enables a local attacker to escalate privileges by modifying recovery partition settings without requiring any user interaction or additional execution privileges.
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= 12.1CVSS 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:3.1/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 checksWork through these to decide whether this CVE applies to you.
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Check Android version is 12.1Run 'getprop ro.build.version.release' or check Settings > About Phone > Android version. For ADB, use: 'adb shell getprop ro.build.version.release'Affected if Version is exactly 12.1 (Android 12L) - earlier or later versions are not affected by this specific CVE
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Verify miniadb component existsCheck if the miniadb binary or service is present on the device. For ADB debugging: 'adb shell ls /system/bin/miniadb' or check process list with 'adb shell ps -A | grep miniadb'Affected if miniadb binary exists and is running on the device - the vulnerability exists in this component
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Check for recovery system property accessAttempt to read recovery-related system properties via ADB: 'adb shell getprop | grep -i recovery' or directly 'adb shell getprop sys.recovery.*' (if such properties exist). Check if read/write access is permitted without root.Affected if Recovery system properties are readable/writable via miniadb - this indicates the insecure default value is present
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Verify ADB debugging mode statusCheck if ADB is enabled on the device: 'adb devices' returns a device, or check Settings > Developer Options > Android Debugging. Also check 'adb shell getprop ro.debuggable'Affected if ADB is enabled and the device is in debuggable state - this enables the attack surface for the vulnerable miniadb component
Device is affected if running Android 12.1 and has the miniadb component with accessible recovery system properties - the insecure default configuration allows modification without authentication.
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 dataThis is a platform-level vulnerability in Android requiring a system firmware update from the device manufacturer (Google patch). Organizations should inventory affected Android-12L devices and coordinate with OEMs/carriers for patch deployment.
- Consultation2.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-39767 — 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-2021-39767 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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