High severity · published Nov 1, 2021
CVE-2021-42694
An issue was discovered in the character definitions of the Unicode Specification through 14.0
8.3
CVSS
4.9%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)4.9% · higher than 92% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
UN
Unicode · Unicode
before 14.0.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-42694
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-42694
Mailing List
http://www.openwall.com/lists/oss-security/2021/11/01/1
Mailing List
http://www.openwall.com/lists/oss-security/2021/11/01/6
Release Notes
http://www.unicode.org/versions/Unicode14.0.0/
Third Party Advisory
https://cwe.mitre.org/data/definitions/1007.html
Third Party Advisory
https://security.gentoo.org/glsa/202210-09
Third Party Advisory
https://trojansource.codes
More from Unicode
8.3
CVE-2021-42574
An issue was discovered in the Bidirectional Algorithm in the Unicode Specification through 14.0
