dbcve.org
AndroidOperating system · Google

CVE-2023-20913

HIGH · 7.8 CVSS v3.1 Published 2023-01-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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 onCreate of PhoneAccountSettingsActivity.java and related files, there is a possible way to mislead the user into enabling a malicious phone account due to a tapjacking/overlay attack. This could lead to local escalation of privilege with User execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-10 Android-11 Android-12 Android-12L Android-13Android ID: A-246933785

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 confidence

A tapjacking/overlay vulnerability in PhoneAccountSettingsActivity.java allows a malicious app to place an overlay on top of the phone account settings UI, tricking users into enabling a malicious phone account. The app fails to detect or block overlays before allowing sensitive account configuration actions, enabling local privilege escalation with user interaction.

MitigationImplement overlay detection (using WindowManager.LayoutParams.FLAG_SECURE or overlay-aware checks) before displaying sensitive phone account configuration UI, and add explicit user confirmation dialogs for enabling new phone accounts to prevent unintended actions.

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:= 10.0= 11.0= 12.0= 12.1= 13.0

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 version
    Go to Settings > About Phone > Android version or run 'adb shell getprop ro.build.version.release'
    Affected if The version is 10.0, 11.0, 12.0, 12.1, or 13.0
  2. Identify apps with overlay permission
    Run 'adb shell dumpsys package -d PERMISSION' and look for 'SYSTEM_ALERT_WINDOW' grants, or check in Settings > Apps > Special access > Display over other apps
    Affected if Any untrusted or unknown app holds the SYSTEM_ALERT_WINDOW permission
  3. Verify PhoneAccountSettingsActivity accessibility
    Run 'adb shell dumpsys package <package>' and look for PhoneAccountSettingsActivity in the package manifest, or inspect the telephony provider APK
    Affected if The PhoneAccountSettingsActivity component is exported and accessible to other apps
  4. Check for sideloaded apps with sensitive permissions
    Review installed apps in Settings > Apps, focusing on sideloaded or unknown sources, and verify their granted permissions
    Affected if Sideloaded apps with telephony or overlay permissions are present on the device

The environment is affected if running Android 10.0-13.0 and any application holds SYSTEM_ALERT_WINDOW permission, allowing a malicious app to overlay the PhoneAccountSettingsActivity and trick users into enabling a malicious phone account.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement overlay detection (using WindowManager.LayoutParams.FLAG_SECURE or overlay-aware checks) before displaying sensitive phone account configuration UI, and add explicit user confirmation dialogs for enabling new phone accounts to prevent unintended actions.

Recommended fix High confidence
  1. 1. Navigate to Settings > System > Security & privacy > Location security on the affected Android device
  2. 2. Check the current Android version and security patch level under Settings > About phone > Android version
  3. 3. If the device is on Android 10, 11, 12, 12L, or 13, it is vulnerable to this tapjacking attack
  4. 4. Apply the latest system update available for the device to receive the security patch that addresses CVE-2023-20913
  5. 5. Alternatively, manually check for updates: Settings > System > Software update > Check for updates
  6. 6. Ensure the security patch level is at least June 2023 or later, which contains the fix for this vulnerability
Caveat Side-loaded apps may need re-installation after factory reset if needed for major version upgrades; some legacy apps may be incompatible with newer Android versions

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

Fix this in Android Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
28.0 hours of engineering $4,880
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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-2023-20913 in production — separate from our analysis above.

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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