CVE-2023-21035

Local privilege escalation via unchecked signing certificates

Published Mar 24, 2023 · Updated Feb 25, 2025

Incorrect authorization in Android 13 BackupHelper allows local users to inherit permissions granted to another app with the same package name. BackupHelper restores backed-up permission state by package name without first verifying that the installed replacement has compatible signing certificates. Exploitation requires a local app to replace a previously granted package during backup restoration, and no user interaction is required.

CVSS severity7.8
High
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Android 13 BackupHelper allows local users to inherit permissions granted to another app with the same package name. BackupHelper restores backed-up permission state by package name without first verifying that the installed replacement has compatible signing certificates. Exploitation requires a local app to replace a previously granted package during backup restoration, and no user interaction is required.

The record

CVE
CVE-2023-21035
Published
Mar 24, 2023
Updated
Feb 25, 2025
Vendor
Google Cloud
Product
Android
Classifications
CWE-863, T1626
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 25, 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?

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  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-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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1626Abuse Elevation Control Mechanism

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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