CVE-2021-21194Public exploitNetwork attack vector

Browser code execution via freed screen-capture object

Published Apr 9, 2021 · Updated Aug 3, 2024

Use after free in Google Chrome screen capture before 89.0.4389.114 allows remote attackers to corrupt heap memory via a crafted HTML page. The screen-capture flow retains and later accesses an object after its lifetime ends when the requesting page closes before approval. Exploitation requires a user to open the page and approve screen sharing after the page closes; successful heap corruption can execute code in the browser context.

CVSS severity8.8
High
EPSS probability1.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use after free in Google Chrome screen capture before 89.0.4389.114 allows remote attackers to corrupt heap memory via a crafted HTML page. The screen-capture flow retains and later accesses an object after its lifetime ends when the requesting page closes before approval. Exploitation requires a user to open the page and approve screen sharing after the page closes; successful heap corruption can execute code in the browser context.

The record

CVE
CVE-2021-21194
Published
Apr 9, 2021
Updated
Aug 3, 2024
Vendor
Google Cloud
Product
Google Chrome
Classifications
CWE-416, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 9, 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 <89.0.4389.114

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Google Cloud · Google Chromeversion=unspecified <89.0.4389.114

Published CVSS scores

8.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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.

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 exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution

Public exploit references

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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