CVE-2023-25730Public exploitNetwork attack vector

UI spoofing via stalled fullscreen navigation

Published Jun 2, 2023 · Updated Jan 10, 2025

Improper fullscreen exit handling in Firefox before 110, Firefox ESR before 102.8, and Thunderbird before 102.8 allows remote attackers to spoof UI. When an out-of-process iframe blocks its content-process main thread during requestFullscreen and then navigates, the parent process fails to exit chrome-document fullscreen. A user must interact with attacker-controlled web content; the resulting indefinite fullscreen state can conceal browser chrome and support convincing page spoofing.

CVSS severity5.4
Medium
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper fullscreen exit handling in Firefox before 110, Firefox ESR before 102.8, and Thunderbird before 102.8 allows remote attackers to spoof UI. When an out-of-process iframe blocks its content-process main thread during requestFullscreen and then navigates, the parent process fails to exit chrome-document fullscreen. A user must interact with attacker-controlled web content; the resulting indefinite fullscreen state can conceal browser chrome and support convincing page spoofing.

The record

CVE
CVE-2023-25730
Published
Jun 2, 2023
Updated
Jan 10, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-1021, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 2, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 10, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <110

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <110
Mozilla · Thunderbirdversion=unspecified <102.8
Mozilla · Firefox ESRversion=unspecified <102.8

Published CVSS scores

5.4CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
5.4NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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.

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

CWE-1021Improper Restriction of Rendered UI Layers or Frames
T1189Drive-by Compromise

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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