CVE-2023-21087

Persistent boot-loop denial via excessive notification groups

Published Apr 19, 2023 · Updated Feb 5, 2025

Uncaught exception handling in Android 11 through 13 allows local users to cause a persistent boot-loop denial of service. PreferencesHelper accepts excessive per-app notification channel groups and reloads them without an enforced group cap, leaving the resulting exception uncaught. A local low-privileged app can trigger the condition without user interaction, leaving the device persistently unable to finish boot.

CVSS severity5.5
Medium
EPSS probability0.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncaught exception handling in Android 11 through 13 allows local users to cause a persistent boot-loop denial of service. PreferencesHelper accepts excessive per-app notification channel groups and reloads them without an enforced group cap, leaving the resulting exception uncaught. A local low-privileged app can trigger the condition without user interaction, leaving the device persistently unable to finish boot.

The record

CVE
CVE-2023-21087
Published
Apr 19, 2023
Updated
Feb 5, 2025
Vendor
Google Cloud
Product
Android
Classifications
CWE-248, T1529
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 19, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 5, 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

5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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-248Uncaught Exception
T1529System Shutdown/Reboot

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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