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

*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 podría 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

References (11)

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://security.gentoo.org/glsa/202202-03	2022-12-09
https://security.gentoo.org/glsa/202208-14	2022-12-09
https://www.debian.org/security/2021/dsa-5026	2022-12-09
https://www.debian.org/security/2022/dsa-5034	2022-12-09
https://www.mozilla.org/security/advisories/mfsa2021-52	2022-12-09
https://www.mozilla.org/security/advisories/mfsa2021-53	2022-12-09
https://www.mozilla.org/security/advisories/mfsa2021-54	2022-12-09
https://access.redhat.com/security/cve/CVE-2021-43542	2021-12-09
https://bugzilla.redhat.com/show_bug.cgi?id=2030112	2021-12-09

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"				< 95.0 Search vendor "Mozilla" for product "Firefox" and version " < 95.0"		-		Affected
Mozilla Search vendor "Mozilla"		Firefox Esr Search vendor "Mozilla" for product "Firefox Esr"				< 91.4.0 Search vendor "Mozilla" for product "Firefox Esr" and version " < 91.4.0"		-		Affected
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