OS Command Injection in Firefox ESR and Mozilla Firefox - CVE-2020-6799
Published: February 11, 2020
Vulnerability identifier: #VU25123
CSH Severity: Medium
CVSS v4: 7.5 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2020-6799
CWE-ID: CWE-78
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary shell commands on the target system.
The vulnerability exists due to improper input validation when opening PDF links from other applications and Firefox is configured as a default PDF reader. A remote unauthenticated attacker can trick the victim into clicking on a specially crafted link and execute arbitrary OS commands on the system.
Note: This issue only affects Windows operating systems and when Firefox is configured as the default handler for non-default filetypes. Other operating systems are unaffected.
Affected software
Firefox ESR
Mozilla Firefox
Gentoo Linux
Slackware Linux
Opensuse
firefox-esr (Alpine package)
Mozilla Firefox
Gentoo Linux
Slackware Linux
Opensuse
firefox-esr (Alpine package)
How to mitigate CVE-2020-6799
Install updates from vendor's website.
Firefox ESR - update to 68.5.0
Mozilla Firefox - update to 73.0
firefox-esr (Alpine package) - update to 68.5.0-r0
Mozilla Firefox - update to 73.0
firefox-esr (Alpine package) - update to 68.5.0-r0