Information disclosure in Brave
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
Vulnerability class: Information Disclosure
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.023 (82.4th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 82.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.023 · newest: 0.023 · change: 0.000
Affected products
- Brave
- Brave Brave-Browser — versions >= 1.17.73, < 1.20.108
Weakness classification (CWE)
References
- github.com/brave/brave-browser/security/advisories/GHSA-mqjf-9x5g-2rv6 (Third Party Advisory)
- github.com/brave/brave-browser/issues/13527 (Patch, Third Party Advisory)
- github.com/brave/brave-core/pull/7769 (Patch, Third Party Advisory)
- github.com/brave/brave-core/commit/12fe321eaad8acc1cbd1d70b4128f687777bcf15 (Patch, Third Party Advisory)
- hackerone.com/reports/1077022 (Permissions Required, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-21323?
- CVE-2021-21323 is a medium-severity vulnerability in Brave, classified under Information Disclosure. CVSS score: 4.3/10. Published 2021-02-23.
- How severe is CVE-2021-21323?
- Medium severity. CVSS v3 base score is 4.3 out of 10.