CVE-2021-23954

Mozilla: Type confusion when using logical assignment operators in JavaScript switch statements

Severity Score

8.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Using the new logical assignment operators in a JavaScript switch statement could have caused a type confusion, leading to a memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

Usando los nuevos operadores de asignación lógica en una declaración de cambio de JavaScript podría haber causado una confusión de tipos, conllevando a una corrupción de la memoria y un bloqueo potencialmente explotable. Esta vulnerabilidad afecta a Firefox versiones anteriores a 85, Thunderbird versiones anteriores a 78,7 y Firefox ESR versiones anteriores a 78,7

The Mozilla Foundation Security Advisory describes this flaw as:

Using the new logical assignment operators in a JavaScript switch statement could have caused a type confusion, leading to a memory corruption and a potentially exploitable crash.

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Medium

Authentication

None

Confidentiality

Partial

Integrity

Partial

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-01-13 CVE Reserved
2021-01-28 CVE Published
2024-08-03 CVE Updated
2024-10-26 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')

CAPEC

References (5)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://www.mozilla.org/security/advisories/mfsa2021-03	2021-03-03
https://www.mozilla.org/security/advisories/mfsa2021-04	2021-03-03
https://www.mozilla.org/security/advisories/mfsa2021-05	2021-03-03
https://access.redhat.com/security/cve/CVE-2021-23954	2021-02-03
https://bugzilla.redhat.com/show_bug.cgi?id=1920648	2021-02-03

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Mozilla Search vendor "Mozilla"		Firefox Search vendor "Mozilla" for product "Firefox"				< 85.0 Search vendor "Mozilla" for product "Firefox" and version " < 85.0"		-		Affected
Mozilla Search vendor "Mozilla"		Firefox Esr Search vendor "Mozilla" for product "Firefox Esr"				< 78.7 Search vendor "Mozilla" for product "Firefox Esr" and version " < 78.7"		-		Affected
Mozilla Search vendor "Mozilla"		Thunderbird Search vendor "Mozilla" for product "Thunderbird"				< 78.7 Search vendor "Mozilla" for product "Thunderbird" and version " < 78.7"		-		Affected