CVE-2017-7766
CVE-2017-7766 is a high-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: High (CVSS 3.x base score 7.8)
- CVSS v2: 4.6
- EPSS exploit prediction: 0% (30th percentile)
- Actively exploited: Not listed in CISA KEV
- Affected product: Mozilla Firefox
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2017-7766?
- 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.
- How severe is CVE-2017-7766?
- CVE-2017-7766 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2017-7766 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2017-7766?
- CVE-2017-7766 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2017-7766?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2017-7766 published?
- CVE-2017-7766 was published on 2018-06-11 and last updated on 2026-06-17.
References
- http://www.securityfocus.com/bid/99057
- http://www.securitytracker.com/id/1038689
- https://bugzilla.mozilla.org/show_bug.cgi?id=1342742
- https://www.mozilla.org/security/advisories/mfsa2017-15/
- https://www.mozilla.org/security/advisories/mfsa2017-16/
Affected products (1)
- cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
More vulnerabilities in Mozilla Firefox
- CVE-2026-4725 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability was fixed in Firefox 149…
- CVE-2026-4692 — Critical (CVSS 10.0): Sandbox escape in the Responsive Design Mode component. This vulnerability was fixed in Firefox 149, Firefox ESR…
- CVE-2026-4689 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component. This vulnerability was…
- CVE-2026-4688 — Critical (CVSS 10.0): Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability was fixed in Firefox…
- CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
- CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…