CVE-2024-9391Public exploitNetwork attack vector

Site spoofing via persistent full-screen state

Published Oct 1, 2024 · Updated Nov 22, 2024

Fullscreen spoofing in Mozilla Firefox Focus for Android before 131 allows remote attackers to impersonate sites via a crafted page. Focus restores the crafted page in full-screen after an Android background reload, hides the address bar, and fails to honor the Back action that should exit full-screen. A user must first enable full-screen and later return to the reloaded app; the persistent display can solicit information under a false site identity but does not itself disclose data.

CVSS severity6.5
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Fullscreen spoofing in Mozilla Firefox Focus for Android before 131 allows remote attackers to impersonate sites via a crafted page. Focus restores the crafted page in full-screen after an Android background reload, hides the address bar, and fails to honor the Back action that should exit full-screen. A user must first enable full-screen and later return to the reloaded app; the persistent display can solicit information under a false site identity but does not itself disclose data.

The record

CVE
CVE-2024-9391
Published
Oct 1, 2024
Updated
Nov 22, 2024
Vendor
Mozilla
Product
Firefox
Classifications
CWE-290, T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 1, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 22, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <131

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <131

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing
T1036Masquerading

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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