Firefox for Android allowed navigations through the `intent://` protocol, which could be used to cause crashes and UI spoofs.

published 2021-11-03 5 y ago modified 2026-08-19 2 mo ago also EUVD-2021-16452

cvss: 8.1; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 54%
public exploits: 0; none known

Firefox for Android allowed navigations through the `intent://` protocol, which could be used to cause crashes and UI spoofs. *This bug only affects Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 92.

Patch / fix

fixed in 1 distros 2

Mozilla Firefox 92

opensuse alpine

firefox-esr openSUSE Tumbleweed 128.5.1-1.1
MozillaFirefox openSUSE Tumbleweed 92.0-1.2

opensuse advisories openSUSE-SU-2024:14572-1 openSUSE-SU-2024:10600-1

firefox Alpine 3.23, Alpine 3.22, Alpine 3.21 +6 more 92.0.1-r0
librewolf Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 92.0.1-r0

alpine advisories ALPINE-CVE-2021-29993

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Exploit prediction

0.73% chance of exploitation in the next 30 days, higher than 54% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	8.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
NVD	2.0	5.8	AV:N/AC:M/Au:N/C:N/I:P/A:P

Affected products

Mozilla Firefox

References

mozilla.org /security/advisories/mfsa2021-38/
vendor-advisory
bugzilla.mozilla.org /buglist.cgi?bug_id=1712242%2C1708767%2C1712240%2C1708544%2C1729259
broken-link

Sources

CVE List CVE-2021-29993
NVD CVE-2021-29993

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary