CVE-2019-11708
Mozilla Firefox and Thunderbird Sandbox Escape Vulnerability
Mozilla Firefox and Thunderbird
Insufficient vetting of parameters passed with the Prompt:Open IPC message between child and parent processes can result in the non-sandboxed parent process opening web content chosen by a compromised child process. When combined with additional vulnerabilities this could result in executing arbitrary code on the user's computer. This vulnerability affects Firefox ESR < 60.7.2, Firefox < 67.0.4, and Thunderbird < 60.7.2.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 23 May 2022. US federal agencies were required to remediate it by 13 June 2022.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 55.9%, which is higher than 99% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Frequently asked questions
Is CVE-2019-11708 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2019-11708.
What does CVE-2019-11708 affect?
CVE-2019-11708 affects Mozilla Firefox and Thunderbird. Insufficient vetting of parameters passed with the Prompt:Open IPC message between child and parent processes can result in the non-sandboxed parent process opening web content chosen by a compromised child process. When combined with additional vulnerabilities this could result in executing arbitrary code on the user's computer. This vulnerability affects Firefox ESR < 60.7.2, Firefox < 67.0.4, and Thunderbird < 60.7.2.
How severe is CVE-2019-11708?
CVE-2019-11708 is rated CRITICAL with a CVSS base score of 10. EPSS puts the probability of exploitation in the next 30 days at 55.9%, higher than 99% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 13 June 2022.
How should organisations respond to CVE-2019-11708?
Apply the vendor patch for Mozilla Firefox and Thunderbird as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.