CVE-2021-29993
Medium
Elevated severity or exploit probability.
CVSS base
8.1
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
EPSS — probability of exploitation (30 days)
0.7%
52.6th percentile
CISA KEV
Not listed
Weakness / dates
—
Published 2021-11-03 · modified 2026-08-19
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | R | Required |
| Scope | U | Unchanged |
| Confidentiality | N | None |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2021-11-03 — Published (NVD)
- 2026-08-19 — Last modified (NVD)
Description
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.
Affected
References
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1712242%2C1708767%2C1712240%2C1708544%2C1729259
- https://www.mozilla.org/security/advisories/mfsa2021-38/
- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1712242%2C1708767%2C1712240%2C1708544%2C1729259
- https://www.mozilla.org/security/advisories/mfsa2021-38/