CVE-2024-1548Public exploitNetwork attack vector

UI spoofing via select overlay on fullscreen warning

Published Feb 20, 2024 · Updated Feb 13, 2025

UI spoofing in Mozilla Firefox before 123, Firefox ESR before 115.8, and Thunderbird before 115.8 allows remote attackers to hide fullscreen warnings. The DOM popup layer lets an HTML select options menu remain above the browser fullscreen notification instead of closing when that warning appears. Exploitation requires a user to enter fullscreen and click the crafted select element with suitable timing; the bounded result is visual spoofing and user confusion.

CVSS severity4.3
Medium
EPSS probability0.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

UI spoofing in Mozilla Firefox before 123, Firefox ESR before 115.8, and Thunderbird before 115.8 allows remote attackers to hide fullscreen warnings. The DOM popup layer lets an HTML select options menu remain above the browser fullscreen notification instead of closing when that warning appears. Exploitation requires a user to enter fullscreen and click the crafted select element with suitable timing; the bounded result is visual spoofing and user confusion.

The record

CVE
CVE-2024-1548
Published
Feb 20, 2024
Updated
Feb 13, 2025
Vendor
Mozilla
Product
Firefox
Classifications
T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 20, 2024CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record 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 <123

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <123
Mozilla · Thunderbirdversion=unspecified <115.8
Mozilla · Firefox ESRversion=unspecified <115.8

Published CVSS scores

4.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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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