CVE-2022-45420Public exploitNetwork attack vector

UI spoofing via unclipped iframe table backgrounds

Published Dec 22, 2022 · Updated Apr 15, 2025

UI spoofing in Mozilla Firefox before 107, Firefox ESR before 102.5, and Thunderbird before 102.5 allows remote attackers to mislead users. The Web Painting code fails to propagate a captured clip to table-column and column-group background items when an intervening frame is a stacking context. A victim must open attacker-controlled content containing tables inside an iframe; crafted CSS margins and backgrounds can then paint over the parent page, but no code execution or data access is reported.

CVSS severity6.5
Medium
EPSS probability0.57%
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 107, Firefox ESR before 102.5, and Thunderbird before 102.5 allows remote attackers to mislead users. The Web Painting code fails to propagate a captured clip to table-column and column-group background items when an intervening frame is a stacking context. A victim must open attacker-controlled content containing tables inside an iframe; crafted CSS margins and backgrounds can then paint over the parent page, but no code execution or data access is reported.

The record

CVE
CVE-2022-45420
Published
Dec 22, 2022
Updated
Apr 15, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-1021
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 22, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 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 <107

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <107
Mozilla · Thunderbirdversion=unspecified <102.5
Mozilla · Firefox ESRversion=unspecified <102.5

Published CVSS scores

6.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/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

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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