CVE-2021-30618Network attack vector

Code execution via headless remote debugging

Published Sep 3, 2021 · Updated Aug 3, 2024

Improper DevTools implementation in Microsoft Edge 93.0.961.38 and earlier allows remote attackers to execute code via crafted HTML. Public records identify the DevTools component but do not disclose the flawed operation performed on the crafted page. Exploitation requires a user to run Edge headless with remote debugging enabled; successful execution runs code in the browser context.

CVSS severity8.8
High
EPSS probability4.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper DevTools implementation in Microsoft Edge 93.0.961.38 and earlier allows remote attackers to execute code via crafted HTML. Public records identify the DevTools component but do not disclose the flawed operation performed on the crafted page. Exploitation requires a user to run Edge headless with remote debugging enabled; successful execution runs code in the browser context.

The record

CVE
CVE-2021-30618
Published
Sep 3, 2021
Updated
Aug 3, 2024
Vendor
Microsoft
Product
Microsoft Edge (Chromium-based)
Classifications
T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 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

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Edge (Chromium-based)version=unspecified

Published CVSS scores

6.8NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
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 exploitUnconfirmed

Weakness, pattern, technique

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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