How severe is CVE-2017-7767?

CVE-2017-7767 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2017-7767 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-7767?

CVE-2017-7767 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-7767?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2017-7767 published?

CVE-2017-7767 was published on 2018-06-11 and last updated on 2026-06-17.

CVE-2017-7767

CVE-2017-7767 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-269.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 2.1
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-269
Affected product: Mozilla Firefox
Published: 2018-06-11
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2017-7767?: 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.
How severe is CVE-2017-7767?: CVE-2017-7767 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2017-7767 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-7767?: CVE-2017-7767 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-7767?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2017-7767 published?: CVE-2017-7767 was published on 2018-06-11 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

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