CVE-2021-0429

Local privilege escalation via stale event queue

Published Apr 13, 2021 · Updated Aug 3, 2024

A use-after-free in Google Cloud Android's System sensor event queue allows local users to escalate privileges via code execution. ALooper retains an event-queue reference after its endpoint disappears; the queue can be destroyed before pollOnce calls it, leaving a stale object in use. Exploitation requires local code execution but no user interaction or additional execution privileges, and successful abuse grants elevated privileges.

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

A use-after-free in Google Cloud Android's System sensor event queue allows local users to escalate privileges via code execution. ALooper retains an event-queue reference after its endpoint disappears; the queue can be destroyed before pollOnce calls it, leaving a stale object in use. Exploitation requires local code execution but no user interaction or additional execution privileges, and successful abuse grants elevated privileges.

The record

CVE
CVE-2021-0429
Published
Apr 13, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Android
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

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-9 Android-10 Android-11 Android-8.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google Cloud · Androidversion=Android-9 Android-10 Android-11 Android-8.1

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/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.

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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-416Use After Free
T1068Exploitation 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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