CVE-2017-7767: Mozilla Firefox

Medium severity, CVSS 5.5. EPSS: 0.3% chance of exploitation in the next 30 days.

The Mozilla Maintenance Service can be invoked by an unprivileged user to overwrite arbitrary files with junk data using the Mozilla Windows Updater, which runs with the Maintenance Service's privileged access. Note: This attack requires local system access and only affects Windows. Other operating systems are not affected. This vulnerability affects Firefox ESR < 52.2 and Firefox < 54.

Affected products

• Mozilla Firefox: before 52.2.0 (fixed in 52.2.0); before 54.0 (fixed in 54.0)

Published 2018-06-11. Last modified 2026-06-17.