CVE-2021-42694
Apache Unicode Homoglyph Identifier Injection Vulnerability
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.
INFO
Published Date :
Nov. 1, 2021, 4:15 a.m.
Last Modified :
Oct. 29, 2024, 2:35 p.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
6.0
Exploitability Score :
1.6
Public PoC/Exploit Available at Github
CVE-2021-42694 has a 6 public PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-42694.
| URL | Resource |
|---|---|
| http://www.openwall.com/lists/oss-security/2021/11/01/1 | Mailing List Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2021/11/01/6 | Mailing List Third Party Advisory |
| http://www.unicode.org/versions/Unicode14.0.0/ | Release Notes Vendor 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 | Third Party Advisory |
| https://www.kb.cert.org/vuls/id/999008 | Third Party Advisory US Government Resource |
| https://www.scyon.nl/post/trojans-in-your-source-code | Exploit Third Party Advisory |
| https://www.unicode.org/reports/tr36/ | Technical Description Vendor Advisory |
| https://www.unicode.org/reports/tr39/ | Technical Description Vendor Advisory |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Map Vulnerabilities into Different Layers of the Container Image
Python
None
A GitHub Action to find Unicode control characters using the Red Hat diagnostic tool https://access.redhat.com/security/vulnerabilities/RHSB-2021-007 to detect RHSB-2021-007 Trojan source attacks (CVE-2021-42574,CVE-2021-42694)
Dockerfile Shell Python
Generate malicious files using recently published homoglyphic-attack (CVE-2021-42694)
Python
None
Ansible Everyday Utilities
ansible ansible-playbooks security security-tools automation linux bsd redhat-enterprise-linux debian ubuntu centos fedora hardening
Shell Perl Python
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-42694 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-42694 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Oct. 29, 2024
Action Type Old Value New Value Added CWE CISA-ADP CWE-94 Removed CWE CISA-ADP CWE-1007 -
CVE Modified by [email protected]
Aug. 04, 2024
Action Type Old Value New Value -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 01, 2024
Action Type Old Value New Value Added CWE CISA-ADP CWE-1007 Added CVSS V3.1 CISA-ADP AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H -
CVE Modified by [email protected]
Jul. 18, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
May. 17, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Apr. 11, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Mar. 21, 2024
Action Type Old Value New Value Added Tag MITRE disputed -
CVE Modified by [email protected]
Nov. 07, 2023
Action Type Old Value New Value Changed Description ** DISPUTED ** 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. 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. -
Modified Analysis by [email protected]
Dec. 06, 2022
Action Type Old Value New Value Changed Reference Type https://security.gentoo.org/glsa/202210-09 No Types Assigned https://security.gentoo.org/glsa/202210-09 Third Party Advisory -
CVE Modified by [email protected]
Oct. 16, 2022
Action Type Old Value New Value Added Reference https://security.gentoo.org/glsa/202210-09 [No Types Assigned] -
Modified Analysis by [email protected]
Sep. 03, 2022
Action Type Old Value New Value Changed Reference Type https://cwe.mitre.org/data/definitions/1007.html No Types Assigned https://cwe.mitre.org/data/definitions/1007.html Third Party Advisory Changed Reference Type https://www.unicode.org/reports/tr36/ No Types Assigned https://www.unicode.org/reports/tr36/ Technical Description, Vendor Advisory Changed Reference Type https://www.unicode.org/reports/tr39/ No Types Assigned https://www.unicode.org/reports/tr39/ Technical Description, Vendor Advisory -
CVE Modified by [email protected]
May. 12, 2022
Action Type Old Value New Value Changed 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. ** DISPUTED ** 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. Added Reference https://www.unicode.org/reports/tr36/ [No Types Assigned] Added Reference https://cwe.mitre.org/data/definitions/1007.html [No Types Assigned] Added Reference https://www.unicode.org/reports/tr39/ [No Types Assigned] -
CWE Remap by [email protected]
May. 03, 2022
Action Type Old Value New Value Changed CWE CWE-94 NVD-CWE-OTHER -
Modified Analysis by [email protected]
Nov. 29, 2021
Action Type Old Value New Value Changed Reference Type https://www.scyon.nl/post/trojans-in-your-source-code No Types Assigned https://www.scyon.nl/post/trojans-in-your-source-code Exploit, Third Party Advisory -
CVE Modified by [email protected]
Nov. 26, 2021
Action Type Old Value New Value Added Reference https://www.scyon.nl/post/trojans-in-your-source-code [No Types Assigned] -
Modified Analysis by [email protected]
Nov. 16, 2021
Action Type Old Value New Value Added CVSS V2 Metadata Victim must voluntarily interact with attack mechanism Removed CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:P/A:P) Added CVSS V2 NIST (AV:N/AC:H/Au:N/C:P/I:P/A:P) Removed CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CVSS V3.1 NIST AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H Changed Reference Type https://www.kb.cert.org/vuls/id/999008 No Types Assigned https://www.kb.cert.org/vuls/id/999008 Third Party Advisory, US Government Resource -
CVE Modified by [email protected]
Nov. 09, 2021
Action Type Old Value New Value Added Reference https://www.kb.cert.org/vuls/id/999008 [No Types Assigned] -
Initial Analysis by [email protected]
Nov. 02, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:P/A:P) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Changed Reference Type http://www.openwall.com/lists/oss-security/2021/11/01/1 No Types Assigned http://www.openwall.com/lists/oss-security/2021/11/01/1 Mailing List, Third Party Advisory Changed Reference Type http://www.openwall.com/lists/oss-security/2021/11/01/6 No Types Assigned http://www.openwall.com/lists/oss-security/2021/11/01/6 Mailing List, Third Party Advisory Changed Reference Type http://www.unicode.org/versions/Unicode14.0.0/ No Types Assigned http://www.unicode.org/versions/Unicode14.0.0/ Release Notes, Vendor Advisory Changed Reference Type https://trojansource.codes No Types Assigned https://trojansource.codes Third Party Advisory Added CWE NIST CWE-94 Added CPE Configuration OR *cpe:2.3:a:unicode:unicode:*:*:*:*:*:*:*:* versions up to (excluding) 14.0.0 -
CVE Modified by [email protected]
Nov. 01, 2021
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2021/11/01/6 [No Types Assigned] -
CVE Modified by [email protected]
Nov. 01, 2021
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2021/11/01/1 [No Types Assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-42694 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-42694
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.54 }} 0.22%
score
0.77791
percentile