CVE-2021-21323

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

• CWE-200

• https://github.com/brave/brave-browser/issues/13527Patch, Third Party Advisory
• https://github.com/brave/brave-browser/security/advisories/GHSA-mqjf-9x5g-2rv6Third Party Advisory
• https://github.com/brave/brave-core/commit/12fe321eaad8acc1cbd1d70b4128f687777bcf15Patch, Third Party Advisory
• https://github.com/brave/brave-core/pull/7769Patch, Third Party Advisory
• https://hackerone.com/reports/1077022Permissions Required, Third Party Advisory
• https://github.com/brave/brave-browser/issues/13527Patch, Third Party Advisory
• https://github.com/brave/brave-browser/security/advisories/GHSA-mqjf-9x5g-2rv6Third Party Advisory
• https://github.com/brave/brave-core/commit/12fe321eaad8acc1cbd1d70b4128f687777bcf15Patch, Third Party Advisory
• https://github.com/brave/brave-core/pull/7769Patch, Third Party Advisory
• https://hackerone.com/reports/1077022Permissions Required, Third Party Advisory

Published

Feb 23, 2021

Last Modified

Jun 17, 2026

Status

Modified

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