CVE-2021-21323

Regression in DNS leakage from Tor windows

CVSS 4.3 MEDIUMEPSS 1.9%CWE-200

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 4.3EPSS 1.9%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

23 Feb 2021Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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

Affected products

brave · brave-browser

Want to know if your infrastructure is exposed to this?

Talk to TrueHacking →

References

https://github.com/brave/brave-browser/issues/13527 https://github.com/brave/brave-browser/security/advisories/GHSA-mqjf-9x5g-2rv6 https://github.com/brave/brave-core/commit/12fe321eaad8acc1cbd1d70b4128f687777bcf15 https://github.com/brave/brave-core/pull/7769 https://hackerone.com/reports/1077022