dbcve.org
AndroidOperating system · Google

CVE-2021-0954

HIGH · 7.3 CVSS v3.1 Published 2021-12-15
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
73/100
Remediation priority · Elevated

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 ResolverActivity, there is a possible user interaction bypass 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-11Android ID: A-143559931

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

In ResolverActivity (Android's intent resolver/app chooser), a tapjacking/overlay vulnerability allows a malicious app to place a transparent overlay on top of the activity, intercepting or redirecting user taps. This bypasses the intended user confirmation or selection action, enabling local privilege escalation without requiring system-level privileges.

MitigationImplement touch filtering in ResolverActivity to detect and block potentially malicious overlays. Android provides FLAG_NOT_TOUCHABLE and other window layout params to prevent overlay interference, and apps should check for visible windows above them using the WindowManager.

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

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
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/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 checks

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

  1. Check your 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 or 11.0 exactly (as specified by the = in the affected versions)
  2. Identify apps with overlay permission
    On Android 10/11, go to Settings > Apps > Special access > Display over other apps to see which apps can draw overlays
    Affected if Any untrusted app has been granted the 'Display over other apps' (SYSTEM_ALERT_WINDOW) permission, creating potential for tapjacking
  3. Verify touch filtering status in ResolverActivity
    Check if ResolverActivity (android/com/android/internal/app/ResolverActivity) has touch filtering enabled by examining window layout flags in the system or using a security tool that inspects window manager state
    Affected if Touch filtering (FLAG_NOT_TOUCHABLE or equivalent) is not implemented in the ResolverActivity running on the device

Your device is affected if it runs Android 10.0 or 11.0 AND has apps with overlay permission that could exploit the tapjacking vulnerability in ResolverActivity.

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 touch filtering in ResolverActivity to detect and block potentially malicious overlays. Android provides FLAG_NOT_TOUCHABLE and other window layout params to prevent overlay interference, and apps should check for visible windows above them using the WindowManager.

Recommended fix High confidence

Upgrade to Android 12 (API level 31) or later, or apply the November 2021 Android Security Patch Level

  1. 1. Navigate to Settings > System > System Update on the affected Android device
  2. 2. Check for and install any available system updates
  3. 3. If updates are available, download and install them to receive the security patch containing the fix for CVE-2021-0954
  4. 4. After updating, verify the device is running Android 12 or later for the most complete protection
  5. 5. Alternatively, if the device cannot be updated to Android 12+, ensure the Android Security Patch Level is set to November 2021 or later
Caveat Upgrading to Android 12 may introduce UI changes and incompatibility with some apps; verify critical applications are compatible before major OS upgrade

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

Fix this in Android Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
30.0 hours of engineering $5,280
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,448.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-0954 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-0954 in production — separate from our analysis above.

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.

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