CVE-2018-5121

Severity: medium (CVSS 5.3 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-06-11 · updated 2026-06-17
Weakness: CWE-20

Description

Low descenders on some Tibetan characters in several fonts on OS X are clipped when rendered in the addressbar. When used as part of an Internationalized Domain Name (IDN) this can be used for domain name spoofing attacks. Note: This attack only affects OS X operating systems. Other operating systems are unaffected. This vulnerability affects Firefox < 58.

Affected products

Mozilla Firefox: through 57.0.4

References

http://www.securityfocus.com/bid/102786
http://www.securitytracker.com/id/1040270
https://bugzilla.mozilla.org/show_bug.cgi?id=1402368
https://www.mozilla.org/security/advisories/mfsa2018-02/
http://www.securityfocus.com/bid/102786
http://www.securitytracker.com/id/1040270
https://bugzilla.mozilla.org/show_bug.cgi?id=1402368
https://www.mozilla.org/security/advisories/mfsa2018-02/

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