CVE-2021-21323

Regression in DNS leakage from Tor windows

Severity Score

5.3

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Brave is an open source web browser with a focus on privacy and security. In Brave versions 1.17.73-1.20.103, the CNAME adblocking feature added in Brave 1.17.73 accidentally initiated DNS requests that bypassed the Brave Tor proxy. Users with adblocking enabled would leak DNS requests from Tor windows to their DNS provider. (DNS requests that were not initiated by CNAME adblocking would go through Tor as expected.) This is fixed in Brave version 1.20.108

Brave es un navegador web de código abierto que se centra en la privacidad y la seguridad. En Brave versiones 1.17.73-1.20.103, la funcionalidad CNAME adblocking agregada en Brave versión 1.17.73, inició accidentalmente peticiones de DNS que omitieron el proxy Brave Tor. Los usuarios con adblocking habilitado filtrarían las peticiones DNS de las ventanas Tor a su proveedor de DNS. (Las peticiones DNS que no fueron iniciadas por el CNAME adblocking pasarían por Tor como se esperaba). Esto se corrigió en Brave versión 1.20.108

*Credits: N/A

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

Low

Integrity

None

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

2020-12-22 CVE Reserved
2021-02-23 CVE Published
2023-11-09 EPSS Updated
2024-08-03 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-200: Exposure of Sensitive Information to an Unauthorized Actor

CAPEC

References (4)

URL	Tag	Source
https://github.com/brave/brave-browser/security/advisories/GHSA-mqjf-9x5g-2rv6	Third Party Advisory

URL	Date	SRC

URL	Date	SRC
https://github.com/brave/brave-browser/issues/13527	2021-03-01
https://github.com/brave/brave-core/commit/12fe321eaad8acc1cbd1d70b4128f687777bcf15	2021-03-01
https://github.com/brave/brave-core/pull/7769	2021-03-01

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Brave Search vendor "Brave"		Brave Search vendor "Brave" for product "Brave"				>= 1.17.73 <= 1.20.103 Search vendor "Brave" for product "Brave" and version " >= 1.17.73 <= 1.20.103"		-		Affected