CVE-2023-21241Public exploit

Local privilege escalation via NFC length overflow

Published Jul 12, 2023 · Updated Nov 6, 2024

Integer overflow in Google Android 11, 12, 12L, and 13 NFC code allows local users to escalate privileges via a crafted tag response. The rw_i93_send_to_upper path adds NFC_HDR_SIZE to an untrusted 16-bit response length without an overflow check, allocating a buffer smaller than the data it forwards. A local user must reach the NFC tag read path with an oversized response; no user interaction is required, and the resulting memory corruption enables privilege escalation.

CVSS severity7.8
High
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Integer overflow in Google Android 11, 12, 12L, and 13 NFC code allows local users to escalate privileges via a crafted tag response. The rw_i93_send_to_upper path adds NFC_HDR_SIZE to an untrusted 16-bit response length without an overflow check, allocating a buffer smaller than the data it forwards. A local user must reach the NFC tag read path with an oversized response; no user interaction is required, and the resulting memory corruption enables privilege escalation.

The record

CVE
CVE-2023-21241
Published
Jul 12, 2023
Updated
Nov 6, 2024
Vendor
Google
Product
Android
Classifications
CWE-190, T1404
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=11
  2. Affected versionversion=12
  3. Affected versionversion=12L
  4. Affected versionversion=13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Google · Androidversion=11; version=12; version=12L; version=13

Published CVSS scores

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 exploitPublished

Weakness, pattern, technique

CWE-190Integer Overflow or Wraparound
T1404Exploitation for Privilege Escalation

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo