CVE-2021-21323
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.
Does this matter?
Lower severity and a low EPSS score (2.26%). Track it; it rarely justifies an emergency change on its own.
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
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- EPSS
- 2.26% probability · 82th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-200
- Affected
- brave/brave
- Source
- security-advisories@github.com
References
- 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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.