// For flags

CVE-2021-43542

Mozilla: XMLHttpRequest error codes could have leaked the existence of an external protocol handler

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.

Usando XMLHttpRequest, un atacante podrĂ­a haber identificado aplicaciones instaladas sondeando los mensajes de error para cargar protocolos externos. Esta vulnerabilidad afecta a Thunderbird versiones anteriores a 91.4.0, Firefox ESR versiones anteriores a 91.4.0 y Firefox versiones anteriores a 95

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-11-08 CVE Reserved
  • 2021-12-08 CVE Published
  • 2024-08-04 CVE Updated
  • 2024-08-23 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-209: Generation of Error Message Containing Sensitive Information
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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< 95.0
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-
Affected
Mozilla
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Firefox Esr
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< 91.4.0
Search vendor "Mozilla" for product "Firefox Esr" and version " < 91.4.0"
-
Affected
Mozilla
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Thunderbird
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< 91.4.0
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-
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
Search vendor "Debian" for product "Debian Linux"
11.0
Search vendor "Debian" for product "Debian Linux" and version "11.0"
-
Affected