CVE-2021-42694Public exploitNetwork attack vector

Code injection via visually confusable identifiers

Published Nov 1, 2021 · Updated Oct 29, 2024

Source-code spoofing in The Unicode Standard allows attackers to inject code through visually confusable identifier names. Distinct Unicode code points can render as nearly identical names, so malicious upstream definitions evade human review and invoke different code. Exploitation requires a reviewer or developer to accept the deceptive source or dependency, after which the downstream build executes the concealed definition.

CVSS severity8.3
High
EPSS probability4.91%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Source-code spoofing in The Unicode Standard allows attackers to inject code through visually confusable identifier names. Distinct Unicode code points can render as nearly identical names, so malicious upstream definitions evade human review and invoke different code. Exploitation requires a reviewer or developer to accept the deceptive source or dependency, after which the downstream build executes the concealed definition.

The record

CVE
CVE-2021-42694
Published
Nov 1, 2021
Updated
Oct 29, 2024
Vendor
The Unicode Consortium
Product
The Unicode Standard
Classifications
CWE-94, T1195.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 1, 2021CVE publishedPublication date reported by the CVE source.
  2. Oct 29, 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=0 <14.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Unicode Consortium · The Unicode Standardversion=0 <14.0.0

Published CVSS scores

8.3CISA-ADPCVSS:3.1/AV:N/AC:H/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.

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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 exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
T1195.001Compromise Software Dependencies and Development Tools

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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