CVE-2021-4221

low-risk

Published 2022-12-22

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.

Do I need to act?

0.18% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 4.3/10 Medium

NETWORK / LOW complexity

Affected Products (1)

Firefox

Affected Vendors

Mozilla

References (4)

Exploit https://bugzilla.mozilla.org/show_bug.cgi?id=1704422

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2021-38/

Exploit https://bugzilla.mozilla.org/show_bug.cgi?id=1704422

Vendor Advisory https://www.mozilla.org/security/advisories/mfsa2021-38/

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low-risk

Severity 18/34 · Moderate

Exploitability 1/34 · Minimal

Exposure 5/34 · Minimal