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CVE-2021-4221 Details

Description

If a domain name contained a RTL character, it would cause the domain to be rendered to the right of the path. This could lead to user confusion and spoofing attacks. <br>*This bug only affects Firefox for Android. Other operating systems are unaffected.*<br>*Note*: Due to a clerical error this advisory was not included in the original announcement, and was added in Feburary 2022. This vulnerability affects Firefox < 92.

Metrics

CVSS 3.x Severity and Vector Strings:

NIST: [email protected]CVSS-B:4.3 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

CNA: CISA-ADPCVSS-B:4.3 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

References to Advisories, Solutions, and Tools

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URL	Source(s)	Tag(s)
https://bugzilla.mozilla.org/show_bug.cgi?id=1704422	CVE	ExploitIssue TrackingVendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-38/	CVE	Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1704422	[email protected]	ExploitIssue TrackingVendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-38/	[email protected]	Vendor Advisory

Weakness Enumeration

CWE-ID	CWE Name	Source
NVD-CWE-Other	Weakness Not in a Standard CWE Category	[email protected]
CWE-1007	Insufficient Visual Distinction of Homoglyphs Presented to User	CISA-ADP

Affected Products

Product	Versions
mozilla firefox	< 92.0
CPE cpe:2.3:a:mozilla:firefox:::::::: Remediation No remediation found in references.
google android	All versions
CPE cpe:2.3:o:google:android:-:::::::* Remediation No remediation found in references.

Change History

6 change records found show changes

Date	Action	Recorded By
Jun 17, 2026	CVE Modified	[email protected]
Jun 17, 2026	CVE Modified	CISA-ADP
Apr 16, 2025	CVE Modified	CISA-ADP
Nov 21, 2024	CVE Modified	CVE
May 14, 2024	CVE Modified	[email protected]
Dec 24, 2022	Initial Analysis	[email protected]