CVE-2019-9801: Firefox will accept any registered Program ID as an external protocol handler and offer to launch this local application when given a matching URL on Windows operating systems

Description

Firefox will accept any registered Program ID as an external protocol handler and offer to launch this local application when given a matching URL on Windows operating systems. This should only happen if the program has specifically registered itself as a "URL Handler" in the Windows registry. *Note: This issue only affects Windows operating systems. Other operating systems are unaffected.*. This vulnerability affects Thunderbird < 60.6, Firefox ESR < 60.6, and Firefox < 66.

CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack vector

Network

Complexity

Low

Privileges

None

User interaction

None

Confidentiality

None

Integrity

Low

Availability

None

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)1.3% · higher than 70% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

FI

Firefox · Mozilla

before 66.0 · source: NVD

FE

Firefox Esr · Mozilla

before 60.6 · source: NVD

TH

Thunderbird · Mozilla

before 60.6 · source: NVD