CVE-2023-20906

Local privilege escalation via retained overlay permission

Published Mar 24, 2023 · Updated Feb 28, 2025

Privilege escalation in Android 11, 12, 12L, and 13 allows local users to retain a privileged overlay permission after an app update. PermissionManagerService.onPackageAddedInternal fails to revoke SYSTEM_ALERT_WINDOW when an app raises its target SDK above 23, preserving a grant that the newer target no longer qualifies to keep. Exploitation requires a locally installed pre-23 app to receive that permission and then be updated to a higher target SDK; no user interaction is required.

CVSS severity7.8
High
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in Android 11, 12, 12L, and 13 allows local users to retain a privileged overlay permission after an app update. PermissionManagerService.onPackageAddedInternal fails to revoke SYSTEM_ALERT_WINDOW when an app raises its target SDK above 23, preserving a grant that the newer target no longer qualifies to keep. Exploitation requires a locally installed pre-23 app to receive that permission and then be updated to a higher target SDK; no user interaction is required.

The record

CVE
CVE-2023-20906
Published
Mar 24, 2023
Updated
Feb 28, 2025
Vendor
Google Cloud
Product
Android
Classifications
T1404
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 28, 2025Record 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-11 Android-12 Android-12L Android-13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google Cloud · Androidversion=Android-11 Android-12 Android-12L Android-13

Published CVSS scores

7.8CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/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.

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

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

T1404Exploitation for Privilege Escalation

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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