Windows Hard Link in Mozilla Firefox - CVE-2019-11736
Published: September 3, 2019
Vulnerability identifier: #VU20821
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-11736
CWE-ID: CWE-65
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to the Mozilla Maintenance Service does not guard against files being hardlinked to another file in the updates directory. A local user can create a hardlink to a privileged file and replace it with malicious one. Successful exploitation of the vulnerability may allow a local us to escalate privileges on the system.
Note, the vulnerability affects Windows installation only.
Affected software
Mozilla Firefox
Firefox ESR
Firefox ESR
How to mitigate CVE-2019-11736
Install updates from vendor's website.
Mozilla Firefox - update to 69.0
Firefox ESR - update to 68.1.0
Firefox ESR - update to 68.1.0