CVE-2021-39779
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 getCallStateUsingPackage of Telecom Service, there is a missing permission check. This could lead to local information disclosure of the call state with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-12LAndroid ID: A-190400974
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 confidenceThe getCallStateUsingPackage method in Android's Telecom Service lacks a permission check, allowing any locally installed application to query sensitive call state information without proper authorization. This enables unprivileged apps to access call metadata (incoming/outgoing/idle states) that should be protected.
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= 12.0CVSS 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
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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.
-
Check Android OS versionGo to Settings > About Phone > Android version, or run 'getprop ro.build.version.release' via ADBAffected if The version is exactly 12.0 (Android 12, not 12L or later)
-
Identify apps with READ_PHONE_STATE permissionReview installed applications and check which hold the READ_PHONE_STATE permission in Settings > Apps > Permissions, or enumerate via 'dumpsys package' commandAffected if Any application without this permission could potentially exploit this flaw to access call state data
Your device is affected if it runs Android 12.0 exactly, since this version contains the unpatched Telecom Service with the missing permission check in getCallStateUsingPackage.
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 Android system updates (Android-12L and later) from Google/OEMs. Enterprise environments may use MDM policies to restrict app permissions and monitor for suspicious apps accessing telecom data.
Android 12L with January 2022 Security Patch Level or later
- 1. Navigate to Settings > System > Security & privacy on the Android device
- 2. Tap on 'Security update' or 'Google Play system update'
- 3. Check for and install any available security updates
- 4. Ensure the device receives the January 2022 Android Security Patch Level (SPL) or later which addresses CVE-2021-39779
- 5. After updating, verify the Telecom Service permissions have been corrected by confirming the missing permission check has been added
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-39779 — 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-2021-39779 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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