SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2019-9812

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.

CRITICAL 9.3EPSS 1.30%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.30%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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 3.1
9.3 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:H
EPSS
1.30% probability · 69th percentile
CISA KEV
Not listed
Affected
mozilla/firefox
Source
security@mozilla.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.