CVE-2021-38492: 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…

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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Attack vector

Network

Complexity

Low

Privileges

None

User interaction

Required

Confidentiality

None

Integrity

High

Availability

None

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)1.2% · higher than 67% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

FI

Firefox · Mozilla

before 92.0; 91.0 before 91.1 · source: NVD

FE

Firefox Esr · Mozilla

before 78.14 · source: NVD

TH

Thunderbird · Mozilla

before 78.14; 91.0 before 91.1 · source: NVD