CVE-2023-21251

VPN authorization via unsanitized HTML label

Published Jul 12, 2023 · Updated Nov 5, 2024

Improper input validation in Google Android 11, 12, 12L, and 13 allows local users to authorize a VPN through a deceptive consent dialog. ConfirmDialog.onCreate renders an app-controlled VPN label as HTML without rejecting line breaks or misleading text, allowing system warnings to be hidden. A malicious VPN app needs user execution privileges and user interaction; successful deception authorizes future VPN connections without further consent.

CVSS severity7.3
High
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Google Android 11, 12, 12L, and 13 allows local users to authorize a VPN through a deceptive consent dialog. ConfirmDialog.onCreate renders an app-controlled VPN label as HTML without rejecting line breaks or misleading text, allowing system warnings to be hidden. A malicious VPN app needs user execution privileges and user interaction; successful deception authorizes future VPN connections without further consent.

The record

CVE
CVE-2023-21251
Published
Jul 12, 2023
Updated
Nov 5, 2024
Vendor
Google
Product
Android
Classifications
CWE-20
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 5, 2024Record 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=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

7.3NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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-20Improper Input Validation

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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