CVE-2021-43534

Mozilla: Memory safety bugs fixed in Firefox 94 and Firefox ESR 91.3

Severity Score

8.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Mozilla developers and community members reported memory safety bugs present in Firefox 93 and Firefox ESR 91.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 94, Thunderbird < 91.3, and Firefox ESR < 91.3.

Los desarrolladores y miembros de la comunidad de Mozilla informaron de bugs de seguridad de memoria presentes en Firefox 93 y Firefox ESR 91.2. Algunos de estos bugs mostraban evidencias de corrupción de memoria y suponemos que con suficiente esfuerzo algunos de ellos podrían haber sido explotados para ejecutar código arbitrario. 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:

Memory safety bugs present in Firefox 93 and Firefox ESR 91.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code

*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

2021-11-08 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-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
CWE-787: Out-of-bounds Write

CAPEC

References (10)

URL	Tag	Source
https://lists.debian.org/debian-lts-announce/2021/12/msg00030.html	Mailing List
https://lists.debian.org/debian-lts-announce/2022/01/msg00001.html	Mailing List

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1606864%2C1712671%2C1730048%2C1735152	2022-03-17
https://www.debian.org/security/2021/dsa-5026	2022-03-17
https://www.debian.org/security/2022/dsa-5034	2022-03-17
https://www.mozilla.org/security/advisories/mfsa2021-48	2022-03-17
https://www.mozilla.org/security/advisories/mfsa2021-49	2022-03-17
https://www.mozilla.org/security/advisories/mfsa2021-50	2022-03-17
https://access.redhat.com/security/cve/CVE-2021-43534	2021-11-10
https://bugzilla.redhat.com/show_bug.cgi?id=2019630	2021-11-10

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"				< 94.0 Search vendor "Mozilla" for product "Firefox" and version " < 94.0"		-		Affected
Mozilla Search vendor "Mozilla"		Firefox Esr Search vendor "Mozilla" for product "Firefox Esr"				< 91.3.0 Search vendor "Mozilla" for product "Firefox Esr" and version " < 91.3.0"		-		Affected
Mozilla Search vendor "Mozilla"		Thunderbird Search vendor "Mozilla" for product "Thunderbird"				< 91.3.0 Search vendor "Mozilla" for product "Thunderbird" and version " < 91.3.0"		-		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