CVE-2021-45884Public exploitNetwork attack vector

DNS request disclosure via CNAME uncloaking

Published Dec 27, 2021 · Updated Aug 4, 2024

Information disclosure in Brave Desktop 1.17 through 1.33 before 1.33.106 allows attackers to learn hostnames via system DNS traffic. ProxySettingsAllowUncloaking fails to reject per-scheme proxy configurations whose fallback is SOCKS, so CNAME lookups use the system resolver. Exposure requires CNAME-based ad blocking and a proxy extension with a SOCKS fallback, and reveals requested hostnames to the system DNS provider.

CVSS severity7.5
High
EPSS probability3.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Information disclosure in Brave Desktop 1.17 through 1.33 before 1.33.106 allows attackers to learn hostnames via system DNS traffic. ProxySettingsAllowUncloaking fails to reject per-scheme proxy configurations whose fallback is SOCKS, so CNAME lookups use the system resolver. Exposure requires CNAME-based ad blocking and a proxy extension with a SOCKS fallback, and reveals requested hostnames to the system DNS provider.

The record

CVE
CVE-2021-45884
Published
Dec 27, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-200
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 27, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:P/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo