// For flags

CVE-2021-43528

Mozilla: JavaScript unexpectedly enabled for the composition area

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

Thunderbird unexpectedly enabled JavaScript in the composition area. The JavaScript execution context was limited to this area and did not receive chrome-level privileges, but could be used as a stepping stone to further an attack with other vulnerabilities. This vulnerability affects Thunderbird < 91.4.0.

Thunderbird habilitó inesperadamente JavaScript en el área de composición. El contexto de ejecución de JavaScript se limitaba a esta área y no recibía privilegios a nivel de cromo, pero podía ser usado como un trampolín para avanzar en un ataque con otras vulnerabilidades. Esta vulnerabilidad afecta a Thunderbird versiones anteriores a 91.4.0

Multiple security issues were discovered in Thunderbird. If a user were tricked into opening a specially crafted website in a browsing context, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information, trick a user into accepting unwanted permissions, conduct header splitting attacks, conduct spoofing attacks, bypass security restrictions, confuse the user, or execute arbitrary code.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low
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
  • 2021-11-08 CVE Reserved
  • 2021-12-08 CVE Published
  • 2024-08-04 CVE Updated
  • 2025-04-13 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-269: Improper Privilege Management
  • CWE-281: Improper Preservation of Permissions
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Mozilla
Search vendor "Mozilla"
 Thunderbird
Search vendor "Mozilla" for product "Thunderbird"
 < 91.4.0
Search vendor "Mozilla" for product "Thunderbird" and version " < 91.4.0"
-
Affected
Debian
Search vendor "Debian"
 Debian Linux
Search vendor "Debian" for product "Debian Linux"
 9.0
Search vendor "Debian" for product "Debian Linux" and version "9.0"
-
Affected
Debian
Search vendor "Debian"
 Debian Linux
Search vendor "Debian" for product "Debian Linux"
 10.0
Search vendor "Debian" for product "Debian Linux" and version "10.0"
-
Affected
Debian
Search vendor "Debian"
 Debian Linux
Search vendor "Debian" for product "Debian Linux"
 11.0
Search vendor "Debian" for product "Debian Linux" and version "11.0"
-
Affected