CVE-2023-20939

Local privilege escalation via unreferenced callback object

Published Feb 28, 2023 · Updated Mar 21, 2025

Improper locking in the wificond event loop in Android 12, 12L, and 13 allows local users to escalate privileges. looper_backed_event_loop.cpp creates an EventLoopCallback without sp::make, so the RefBase object does not receive its required initial strong reference and concurrent activity can corrupt memory. A local foothold is required, but no additional execution privileges or user interaction are needed to obtain higher system privileges.

CVSS severity7.8
High
EPSS probability0.07%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in the wificond event loop in Android 12, 12L, and 13 allows local users to escalate privileges. looper_backed_event_loop.cpp creates an EventLoopCallback without sp::make, so the RefBase object does not receive its required initial strong reference and concurrent activity can corrupt memory. A local foothold is required, but no additional execution privileges or user interaction are needed to obtain higher system privileges.

The record

CVE
CVE-2023-20939
Published
Feb 28, 2023
Updated
Mar 21, 2025
Vendor
Google Cloud
Product
Android
Classifications
CWE-667, T1404
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 28, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 21, 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-12 Android-12L Android-13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google Cloud · Androidversion=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.

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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-667Improper Locking
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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