CVE-2021-38492

MEDIUM

Firefox < 92.0 and Firefox ESR < 78.14 - Unauthenticated Arbitrary Code Execution via mk Scheme Delegation

Title source: llm
STIX 2.1

Description

When delegating navigations to the operating system, Firefox would accept the `mk` scheme which might allow attackers to launch pages and execute scripts in Internet Explorer in unprivileged mode. *This bug only affects Firefox for Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 92, Thunderbird < 91.1, Thunderbird < 78.14, Firefox ESR < 78.14, and Firefox ESR < 91.1.

References (7)

Core 7
Core References
Exploit, Issue Tracking, Vendor Advisory x_refsource_misc
https://bugzilla.mozilla.org/show_bug.cgi?id=1721107
Third Party Advisory vendor-advisory x_refsource_gentoo
https://security.gentoo.org/glsa/202208-14

Scores

CVSS v3 6.5
EPSS 0.0041
EPSS Percentile 61.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Details

Status published
Products (3)
mozilla/firefox < 92.0
mozilla/firefox_esr < 78.14
mozilla/thunderbird < 78.14
Published Nov 03, 2021
Tracked Since Feb 18, 2026