CVE-2023-21242Network attack vector

Unauthenticated privilege escalation via unvalidated certificate chain

Published Aug 14, 2023 · Updated Oct 9, 2024

Certificate-validation bypass in Google Android 13 allows remote attackers to gain privileges by impersonating an enterprise Wi-Fi server. InsecureEapNetworkHandler.isServerCertChainValid accepts a server-supplied full certificate chain for trust-on-first-use after checking names and CA flags but without cryptographic path validation. Exploitation requires an insecure EAP network using trust-on-first-use, but no existing privileges or user interaction.

CVSS severity9.8
Critical
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Certificate-validation bypass in Google Android 13 allows remote attackers to gain privileges by impersonating an enterprise Wi-Fi server. InsecureEapNetworkHandler.isServerCertChainValid accepts a server-supplied full certificate chain for trust-on-first-use after checking names and CA flags but without cryptographic path validation. Exploitation requires an insecure EAP network using trust-on-first-use, but no existing privileges or user interaction.

The record

CVE
CVE-2023-21242
Published
Aug 14, 2023
Updated
Oct 9, 2024
Vendor
Google
Product
Android
Classifications
T1557.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 14, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 9, 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=13

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google · Androidversion=13

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1557.004Evil Twin

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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