CVE-2023-29533Public exploitNetwork attack vector

UI spoofing via obscured fullscreen notification

Published Jun 2, 2023 · Updated Jan 9, 2025

Fullscreen notification spoofing in Mozilla browsers and Thunderbird allows remote attackers to mislead users through a crafted website. The DOM focus path fails to leave fullscreen when a same-named popup is raised after repeated fullscreen requests, allowing the popup to cover the notification. User interaction with the site is required; Firefox, Firefox for Android, and Focus before 112 and Firefox ESR and Thunderbird before 102.10 are affected, with spoofing as the bounded consequence.

CVSS severity4.3
Medium
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Fullscreen notification spoofing in Mozilla browsers and Thunderbird allows remote attackers to mislead users through a crafted website. The DOM focus path fails to leave fullscreen when a same-named popup is raised after repeated fullscreen requests, allowing the popup to cover the notification. User interaction with the site is required; Firefox, Firefox for Android, and Focus before 112 and Firefox ESR and Thunderbird before 102.10 are affected, with spoofing as the bounded consequence.

The record

CVE
CVE-2023-29533
Published
Jun 2, 2023
Updated
Jan 9, 2025
Vendor
Mozilla
Product
Firefox
Classifications
T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 2, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 9, 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 <112

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <112
Mozilla · Thunderbirdversion=unspecified <102.10
Mozilla · Firefox for Androidversion=unspecified <112
Mozilla · Firefox Focus for Androidversion=unspecified <112
Mozilla · Firefox ESRversion=unspecified <102.10

Published CVSS scores

4.3NIST NVDCVSS: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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