CVE-2021-0386

Local privilege escalation via overlaid USB confirmation

Published Mar 10, 2021 · Updated Aug 3, 2024

Tapjacking in UsbConfirmActivity in Google Android 11 allows local users to gain elevated privileges through an overlaid USB confirmation. The activity's onCreate path leaves the confirmation window open to non-system dialogs because it does not set the flag that hides those overlays. Exploitation requires an attacker-controlled app with User execution privileges and user interaction with the obscured prompt, after which the app gains permissions intended for the approved USB handler.

CVSS severity7.8
High
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Tapjacking in UsbConfirmActivity in Google Android 11 allows local users to gain elevated privileges through an overlaid USB confirmation. The activity's onCreate path leaves the confirmation window open to non-system dialogs because it does not set the flag that hides those overlays. Exploitation requires an attacker-controlled app with User execution privileges and user interaction with the obscured prompt, after which the app gains permissions intended for the approved USB handler.

The record

CVE
CVE-2021-0386
Published
Mar 10, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-1021
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 10, 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?

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  1. Affected versionversion=Android-11

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google Cloud · Androidversion=Android-11

Published CVSS scores

6.8NIST National Vulnerability DatabaseAV:N/AC:M/Au:N/C:P/I:P/A:P
7.8NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1021Improper Restriction of Rendered UI Layers or Frames

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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