CVE-2021-0438

Local privilege escalation via untracked overlay windows

Published Apr 13, 2021 · Updated Aug 3, 2024

Tapjacking in Android 8.1, 9, and 10 allows local users to gain elevated privileges by inducing interaction with an obscured window. The NO_INPUT_CHANNEL flag lets a non-system caller create an overlay unknown to InputDispatcher, so the covered window receives input without FLAG_OBSCURED. Exploitation requires a malicious local application and user interaction; the consequence is privilege elevation through input delivered to the hidden target.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Tapjacking in Android 8.1, 9, and 10 allows local users to gain elevated privileges by inducing interaction with an obscured window. The NO_INPUT_CHANNEL flag lets a non-system caller create an overlay unknown to InputDispatcher, so the covered window receives input without FLAG_OBSCURED. Exploitation requires a malicious local application and user interaction; the consequence is privilege elevation through input delivered to the hidden target.

The record

CVE
CVE-2021-0438
Published
Apr 13, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-1021, T1404
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Android-8.1 Android-9 Android-10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Google Cloud · Androidversion=Android-8.1 Android-9 Android-10

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
4.4NIST NVDAV:L/AC:M/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1021Improper Restriction of Rendered UI Layers or Frames
T1404Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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