CVE-2023-21102

Local privilege escalation via shadow stack bypass

Published May 15, 2023 · Updated Jan 24, 2025

Privilege escalation in the Android kernel allows local users to gain elevated privileges through the ARM64 EFI runtime wrapper. __efi_rt_asm_wrapper reloads the shadow call stack pointer from the ordinary stack, creating a gadget that defeats shadow stack protection. Exploitation requires local low-privileged access on an ARM64 device using EFI runtime services, needs no user interaction, and can compromise kernel confidentiality and integrity.

CVSS severity7.8
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Privilege escalation in the Android kernel allows local users to gain elevated privileges through the ARM64 EFI runtime wrapper. __efi_rt_asm_wrapper reloads the shadow call stack pointer from the ordinary stack, creating a gadget that defeats shadow stack protection. Exploitation requires local low-privileged access on an ARM64 device using EFI runtime services, needs no user interaction, and can compromise kernel confidentiality and integrity.

The record

CVE
CVE-2023-21102
Published
May 15, 2023
Updated
Jan 24, 2025
Vendor
Google Cloud
Product
Android
Classifications
CWE-754, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 24, 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 kernel

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google Cloud · Androidversion=Android kernel

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-754Improper Check for Unusual or Exceptional Conditions
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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