CVE-2023-20940

Local privilege escalation via omitted init_boot resigning

Published Feb 28, 2023 · Updated Mar 21, 2025

Improper cryptographic verification in Android 13 allows local users to replace a boot partition and gain elevated privileges. The sign_target_files_apks.py release-signing tool omitted init_boot from its AVB key, algorithm, and extra-argument handling, so the Android 13 init_boot image was not re-signed as intended. A target must use the separate init_boot image produced through the affected release-signing path; exploitation needs local low-privileged access but no user interaction.

CVSS severity7.8
High
EPSS probability0.06%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper cryptographic verification in Android 13 allows local users to replace a boot partition and gain elevated privileges. The sign_target_files_apks.py release-signing tool omitted init_boot from its AVB key, algorithm, and extra-argument handling, so the Android 13 init_boot image was not re-signed as intended. A target must use the separate init_boot image produced through the affected release-signing path; exploitation needs local low-privileged access but no user interaction.

The record

CVE
CVE-2023-20940
Published
Feb 28, 2023
Updated
Mar 21, 2025
Vendor
Google Cloud
Product
Android
Classifications
CWE-347, T1068
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-13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google Cloud · Androidversion=Android-13

Published CVSS scores

7.8CISA ADP VulnrichmentCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8NVDCVSS: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-347Improper Verification of Cryptographic Signature
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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