// For flags

CVE-2021-38506

Mozilla: Firefox could be coaxed into going into fullscreen mode without notification or warning

Severity Score

4.3
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

Through a series of navigations, Firefox could have entered fullscreen mode without notification or warning to the user. This could lead to spoofing attacks on the browser UI including phishing. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

Mediante de una serie de navegaciones, Firefox podría haber entrado en modo de pantalla completa sin notificación o advertencia al usuario. Esto podría conllevar a ataques de suplantación de identidad en la Interfaz de Usuario del navegador, incluido el phishing. Esta vulnerabilidad afecta a Firefox versiones anteriores a 94, Thunderbird versiones anteriores a 91.3, y Firefox ESR versiones anteriores a 91.3

The Mozilla Foundation Security Advisory describes this flaw as:

Through a series of navigations, Firefox could have entered fullscreen mode without notification or warning to the user. This could lead to spoofing attacks on the browser UI including phishing.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-08-10 CVE Reserved
  • 2021-11-03 CVE Published
  • 2024-08-04 CVE Updated
  • 2024-10-16 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-1021: Improper Restriction of Rendered UI Layers or Frames
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Mozilla
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Firefox
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< 94.0
Search vendor "Mozilla" for product "Firefox" and version " < 94.0"
-
Affected
Mozilla
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Firefox Esr
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< 91.3.0
Search vendor "Mozilla" for product "Firefox Esr" and version " < 91.3.0"
-
Affected
Mozilla
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Thunderbird
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< 91.3.0
Search vendor "Mozilla" for product "Thunderbird" and version " < 91.3.0"
-
Affected
Debian
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Debian Linux
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9.0
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-
Affected
Debian
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Debian Linux
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10.0
Search vendor "Debian" for product "Debian Linux" and version "10.0"
-
Affected
Debian
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Debian Linux
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11.0
Search vendor "Debian" for product "Debian Linux" and version "11.0"
-
Affected