CVE-2021-21323 | BDVDB-2026-149557 Detail

bravebrave-browser

Description#

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

Impact#

Per CVSS v3.1: confidentiality impact low, integrity impact none, availability impact none. Attack vector: network.

Weaknesses#

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References#

Exploit#

No public exploit known

History#

Version 12021-02-23Record published in the CVE List.
Version 22024-08-03Most recent update recorded in the CVE List.

Published

Published: 2021-02-23
Last modified: 2024-08-03

Vendor information

Vendor: brave
Product: brave-browser

All brave vulnerabilities

Score

4.3 Medium

EPSS

2.2%, Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 83.1.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Information Disclosure

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
>= 1.17.73, < 1.20.108
Fixed
Not stated

Scoring System

CVSS v4.0

Not available

CVSS v3.1

4.3 Medium

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Privileges Required	None
User Interaction	Required
Scope	Unchanged
Confidentiality	Low
Integrity	None
Availability	None

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).