AndroidOperating system · Google

CVE-2023-21378

HIGH · 7.8 CVSS v3.1 Published 2023-10-30
Fix available
A fix is available. Upgrade to 14.0 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

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 · unedited
In Telecomm, there is a possible way to silence the ring for calls of secondary users due to a missing permission check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.

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 confidence

This is a local privilege escalation vulnerability in Android's Telecomm framework service. The missing permission check allows a local attacker to silence ringtones for secondary user calls without proper authorization, effectively bypassing intended access controls in the multi-user calling system.

MitigationApply the vendor patch for CVE-2023-21378 which adds proper permission validation in the Telecomm component to enforce authorization checks before allowing modification of call ringing settings for secondary users.

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
AndroidOperating system
Affected:< 14.0

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Check Android OS version
    Navigate to Settings > About Phone > Android version, or execute 'getprop ro.build.version.release' via ADB shell
    Affected if Version number is less than 14.0
  2. Identify configured users
    Run 'pm list users' via ADB shell to list all user accounts on the device
    Affected if Multiple user accounts exist on a device running Android below 14.0
  3. Verify Telecomm framework is accessible
    Execute 'dumpsys telecom' via ADB shell to confirm the Telecomm service is running and accessible
    Affected if Telecomm service is active on Android version below 14.0

Device is affected if it runs Android versions below 14.0 with multiple user accounts configured, as the missing permission check in Telecomm can be exploited to bypass access controls on secondary user call ringing settings.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 14.0 or later
Fixed in 14.0
Interim mitigation

Apply the vendor patch for CVE-2023-21378 which adds proper permission validation in the Telecomm component to enforce authorization checks before allowing modification of call ringing settings for secondary users.

Recommended fix High confidence

Android 14.0

  1. Verify the current Android version by going to Settings > About Phone > Android version
  2. Check if your device manufacturer has released Android 14.0 (or a patch that includes the CVE-2023-21378 fix) for your specific device model
  3. If Android 14.0 is available, back up all important data on the device
  4. Initiate the system update through Settings > System > Software Update > Download and install
  5. Ensure the device is connected to Wi-Fi and has sufficient battery (or is charging) before starting the update
  6. After the update completes, verify the Android version shows 14.0 or later
Caveat Upgrading to Android 14 may cause incompatibility with some apps or custom configurations; review app compatibility and back up data before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Android Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA6.0 h
30.0 hours of engineering $5,120
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,192.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2023-21378 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-21378 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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