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CVE Record

CVE-2021-42694: An issue was discovered in the character definitions of the Unicode Specification through 14.0.

An issue was discovered in the character definitions of the Unicode Specification through 14.0. The specification allows an adversary to produce source code identifiers such as function names using homoglyphs that render visually identical to a target identifier. Adversaries can leverage this to inject code via adversarial identifier definitions in upstream software dependencies invoked deceptively in downstream software. NOTE: the Unicode Consortium offers the following alternative approach to presenting this concern. An issue is noted in the nature of international text that can affect applications that implement support for The Unicode Standard (all versions). Unless mitigated, an adversary could produce source code identifiers using homoglyph characters that render visually identical to but are distinct from a target identifier. In this way, an adversary could inject adversarial identifier definitions in upstream software that are not detected by human reviewers and are invoked deceptively in downstream software. The Unicode Consortium has documented this class of security vulnerability in its document, Unicode Technical Report #36, Unicode Security Considerations. The Unicode Consortium also provides guidance on mitigations for this class of issues in Unicode Technical Standard #39, Unicode Security Mechanisms.

HighCVSS 8.3Not KEV-listedUpdated
Glexia's TakeAutomated analysis

Security readout for executives and security teams

This CVE describes a source-code deception risk, not a single vulnerable product. Unicode homoglyph characters can make one identifier look like another while remaining different to compilers. A malicious dependency could hide behavior that human reviewers miss, creating software supply-chain risk where Unicode identifiers are allowed and not checked. Exposure is most likely in development pipelines, code review, and upstream dependency intake for languages or tools that accept Unicode identifiers without confusable-character controls. The source bundle lists no specific affected product or version. Treat this as a supply-chain and secure-development control gap. It is high severity, but urgency depends on whether your codebases and dependency review processes allow unchecked Unicode identifiers. Mitigation focus: Apply Unicode TR36 and TR39 security guidance for confusable text handling.; Enable compiler, IDE, and linter warnings for confusable or mixed-script identifiers where available.; Restrict source identifiers to approved scripts or ASCII where business needs allow..

Prepared

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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ATT&CK lookup starting points

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cwe · medium confidence lookup

CWE-94: Code execution behavior lookup

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cve · low confidence lookup

CVE-2021-42694 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
8.3 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

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1CVSS vectors
0Timeline events
0ADP providers
8Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
8.3CVSS 3.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H1.66Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

8.3High
CVSS 3.1 vector shape for CVE-2021-42694Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone
Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-94 · source CWE mapping

Improper Control of Generation of Code ('Code Injection')

Improper Control of Generation of Code ('Code Injection') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.