CVE-2021-39790
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 Dialer, there is a possible way to manipulate visual voicemail settings due to a missing permission check. 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-186405146
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 confidenceThis is a local privilege escalation vulnerability in the Android Dialer application. The issue stems from a missing permission check in the visual voicemail settings functionality, which allows a local attacker to manipulate these settings without proper authorization. User interaction is required for exploitation.
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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Check Android versionGo to Settings > About Phone > Android version or run 'getprop ro.build.version.release' in ADB shellAffected if Version equals 12.1 (the only affected version listed)
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Verify Dialer application is installedCheck for com.android.dialer package in Settings > Apps or run 'pm list packages | grep dialer' in ADB shellAffected if Dialer app is present on the device
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Confirm Visual Voicemail is accessibleOpen Dialer app > Settings > Voicemail or check if Visual Voicemail settings menu exists under Calls settingsAffected if Visual Voicemail settings interface is present and accessible
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Check for the missing permission enforcementInspect the Dialer app's visual voicemail settings code (A-186405146 patch reference) or verify if any permission prompt appears when accessing visual voicemail settings without proper authorizationAffected if No permission validation occurs when manipulating visual voicemail settings
Environment is affected if running Android 12.1 with the Dialer app installed and Visual Voicemail settings are accessible without proper permission checks.
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 vendor security patch (A-186405146) that implements proper permission validation in the Dialer app's visual voicemail settings code path.
Android 12L with April 2022 security patch level or later (including Android 13)
- Ensure your Android device is running the latest system software by checking for updates in Settings > System > Software Update
- Alternatively, update the Google Phone (Dialer) app through Google Play Store to receive the security fix
- Verify the patch level after update: go to Settings > About Phone > Security Patch Level and confirm it shows April 2022 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing6.0 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 $4,096.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-39790 — 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-2021-39790 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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