CVE-2019-9812
Mozilla: Sandbox escape through Firefox Sync
Severity
ImportantRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · September 3, 2019
Updated · November 21, 2025
Description
Given a compromised sandboxed content process due to a separate vulnerability, it is possible to escape that sandbox by loading accounts.firefox.com in that process and forcing a log-in to a malicious Firefox Sync account. Preference settings that disable the sandbox are then synchronized to the local machine and the compromised browser would restart without the sandbox if a crash is triggered. This vulnerability affects Firefox ESR < 60.9, Firefox ESR < 68.1, and Firefox < 69.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 9.3CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:H
CWE-250 · Execution with Unnecessary Privileges