CVE-2017-7817: Mozilla Firefox vulnerability

CVE-2017-7817: A spoofing vulnerability can occur when a page switches to fullscreen mode without user notification, allow...

A spoofing vulnerability can occur when a page switches to fullscreen mode without user notification, allowing a fake address bar to be displayed. This allows an attacker to spoof which page is actually loaded and in use. Note: This attack only affects Firefox for Android. Other operating systems are not affected. This vulnerability affects Firefox < 56.

UnknownCVSS not scoredNot KEV-listedUpdatedAug 5, 2024, 16:12 UTC (UTC+00:00)

Security readout for executives and security teams

CVE-2017-7817 lets a malicious page on Firefox for Android switch to fullscreen without notifying the user, then show a fake address bar. This can mislead users about which site they are using. The source bundle says only Firefox for Android is affected, specifically Firefox versions before 56. Exposure is most likely on unmanaged or legacy Android devices still running Firefox for Android before version 56. Modern supported Firefox installations should not be assumed affected from the provided sources. Treat this as a legacy mobile-browser phishing risk. It is not presented as actively exploited or remotely code-executing, but affected devices could mislead users during sensitive sessions. Prioritize cleanup if your environment still permits old Firefox for Android versions. Mitigation focus: Inventory Android devices for Firefox versions before 56.; Upgrade Firefox for Android to version 56 or a current supported release.; Remove or restrict legacy Firefox for Android where upgrade is not possible..

Prepared: Jun 7, 2026, 06:44 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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Vulnerability profileCVE Program record

Severity: Unknown
CVSS: Not scored
Known Exploited: No
Published: Jun 11, 2018, 21:00 UTC (UTC+00:00)

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors

0Timeline events

0ADP providers

3Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

CVE List V5 sourceCVE List V5
https://www.mozilla.org/security/advisories/mfsa2017-21/CVE reference · x_refsource_CONFIRM
https://bugzilla.mozilla.org/show_bug.cgi?id=1356596CVE reference · x_refsource_CONFIRM

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus

MozillaFirefoxunspecifiedListed

Weakness

CWE details

No CWE listed

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