VulnerabilityModified

CVE-2017-7766

HIGH 7.8EPSS 0.37%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.37%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

An attack using manipulation of "updater.ini" contents, used by the Mozilla Windows Updater, and privilege escalation through the Mozilla Maintenance Service to allow for arbitrary file execution and deletion by the Maintenance Service, which has 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.

CVSS 3.0: 7.8 HIGHCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.37% probability · 31th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Affected: mozilla/firefox
Source: security@mozilla.org

EPSS trend

EPSS 0.4% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

http://www.securityfocus.com/bid/99057Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1038689Third Party Advisory, VDB Entry
https://bugzilla.mozilla.org/show_bug.cgi?id=1342742Issue Tracking, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2017-15/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2017-16/Vendor Advisory
http://www.securityfocus.com/bid/99057Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1038689Third Party Advisory, VDB Entry
https://bugzilla.mozilla.org/show_bug.cgi?id=1342742Issue Tracking, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2017-15/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2017-16/Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.