CVE-2021-30571Network attack vector

Sandbox escape via undisclosed DevTools policy bypass

Published Aug 3, 2021 · Updated Aug 3, 2024

Incorrect authorization in Google Chrome before 92.0.4515.107 allows attackers to escape its sandbox via a DevTools policy bypass. Google identifies insufficient policy enforcement in DevTools but has not publicly disclosed the affected check or the operation it authorizes. Exploitation requires a user to install a malicious extension and open a crafted HTML page, after which the extension escapes the browser sandbox.

CVSS severity9.6
Critical
EPSS probability1.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Google Chrome before 92.0.4515.107 allows attackers to escape its sandbox via a DevTools policy bypass. Google identifies insufficient policy enforcement in DevTools but has not publicly disclosed the affected check or the operation it authorizes. Exploitation requires a user to install a malicious extension and open a crafted HTML page, after which the extension escapes the browser sandbox.

The record

CVE
CVE-2021-30571
Published
Aug 3, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-863, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 3, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=unspecified <92.0.4515.107

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=unspecified <92.0.4515.107

Published CVSS scores

9.6NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization
T1203Exploitation for Client Execution

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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