CVE-2023-21111

Emergency-call denial via unbounded phone account fields

Published May 15, 2023 · Updated Jan 31, 2025

Improper input validation in Android 11 through 13 allows local users to interrupt access to emergency services without user interaction. PhoneAccountRegistrar accepts oversized PhoneAccount strings, URI-scheme lists, extras, or icons and serializes them into state without bounds checks, allowing exceptions to disrupt telecom account handling. A locally running app needs no additional execution privileges; exploitation prevents emergency calling rather than exposing or altering data.

CVSS severity5.5
Medium
EPSS probability0.09%
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 Android 11 through 13 allows local users to interrupt access to emergency services without user interaction. PhoneAccountRegistrar accepts oversized PhoneAccount strings, URI-scheme lists, extras, or icons and serializes them into state without bounds checks, allowing exceptions to disrupt telecom account handling. A locally running app needs no additional execution privileges; exploitation prevents emergency calling rather than exposing or altering data.

The record

CVE
CVE-2023-21111
Published
May 15, 2023
Updated
Jan 31, 2025
Vendor
Google Cloud
Product
Android
Classifications
CWE-1284, CWE-20, T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 31, 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-11 Android-12 Android-12L Android-13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Google Cloud · Androidversion=Android-11 Android-12 Android-12L Android-13

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.2CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1284Improper Validation of Specified Quantity in Input
CWE-20Improper Input Validation
T1499Endpoint Denial of Service

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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