CVE-2021-4323Network attack vector

Local file disclosure via insufficient extension validation

Published Jul 28, 2023 · Updated Feb 13, 2025

Insufficient input validation in Google Chrome Extensions before 90.0.4430.72 allows attackers to access local files through a crafted extension. Google has not published the specific Extensions code locus or the incorrect operation performed on extension-controlled input. Exploitation requires a user to install the malicious extension, after which it can read local files but has no reported ability to modify them or disrupt the browser.

CVSS severity6.5
Medium
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient input validation in Google Chrome Extensions before 90.0.4430.72 allows attackers to access local files through a crafted extension. Google has not published the specific Extensions code locus or the incorrect operation performed on extension-controlled input. Exploitation requires a user to install the malicious extension, after which it can read local files but has no reported ability to modify them or disrupt the browser.

The record

CVE
CVE-2021-4323
Published
Jul 28, 2023
Updated
Feb 13, 2025
Vendor
Google Cloud
Product
Google Chrome
Classifications
T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 28, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 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=90.0.4430.72 <90.0.4430.72

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=90.0.4430.72 <90.0.4430.72

Published CVSS scores

6.5UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1204.002User Execution: Malicious File

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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