CVE-2021-39771
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 Settings, there is a possible way to misrepresent which app wants to add a wifi network due to improper input validation. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-12LAndroid ID: A-198661951
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 Android Settings app (Android-12L), improper input validation allows a malicious app to misrepresent its identity when requesting to add a WiFi network. This enables local privilege escalation where an app can trick users into adding malicious networks while appearing to come from a trusted app.
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
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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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Verify Android versionGo to Settings > About phone and check the Android version. Alternatively, run 'adb shell getprop ro.build.version.release'Affected if The Android version is exactly 12.1 (Android-12L)
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Confirm Settings app packageRun 'adb shell dumpsys package com.android.settings' to retrieve the Settings app package detailsAffected if The package com.android.settings is installed and matches the Android-12L baseline
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Check Settings app versionRun 'adb shell pm dump com.android.settings | grep versionName' or view the app info in Settings > Apps > Settings > VersionAffected if The Settings app version predates the March 2022 security patch (no specific version number in advisory; compare against your patch date)
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Identify WiFi add network flowInspect any third-party apps that request WiFi configuration adding via intents. Check if any app uses ACTION_WIFI_ADD_NETWORK or similar APIs to request network addition through SettingsAffected if A malicious app can craft a request that spoofs the originating app's identity when adding WiFi networks
If the device runs Android 12.1 and the Settings app has not received the March 2022 security bulletin patch, the improper input validation in the WiFi network addition flow is present and apps can spoof their identity.
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.
dbcve · scopedApply the Android-12L security update (patched in the March 2022 Android Security Bulletin) to address the improper input validation in the Settings application.
Android 13 or later with February 2022 security patch level (or newer)
- 1. Navigate to Settings on the Android device
- 2. Scroll down and tap on 'System' or 'About phone'
- 3. Tap on 'Software update' or 'System update'
- 4. Check for and install any available updates
- 5. Ensure the device receives the latest Android security patch level
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-39771 — 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-2021-39771 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data