How severe is CVE-2021-45884?

CVE-2021-45884 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-45884 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-45884?

CVE-2021-45884 affects Brave. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-45884?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-45884 published?

CVE-2021-45884 was published on 2021-12-27 and last updated on 2026-06-17.

CVE-2021-45884

CVE-2021-45884 is a high-severity vulnerability in Brave with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 4.3
EPSS exploit prediction: 3% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Brave
Published: 2021-12-27
Last modified: 2026-06-17

Description

In Brave Desktop 1.17 through 1.33 before 1.33.106, when CNAME-based adblocking and a proxying extension with a SOCKS fallback are enabled, additional DNS requests are issued outside of the proxying extension using the system's DNS settings, resulting in information disclosure. NOTE: this issue exists because of an incomplete fix for CVE-2021-21323 and CVE-2021-22916.

Frequently asked questions

What is CVE-2021-45884?: In Brave Desktop 1.17 through 1.33 before 1.33.106, when CNAME-based adblocking and a proxying extension with a SOCKS fallback are enabled, additional DNS requests are issued outside of the proxying extension using the system's DNS settings, resulting in information disclosure. NOTE: this issue exists because of an incomplete fix for CVE-2021-21323 and CVE-2021-22916.
How severe is CVE-2021-45884?: CVE-2021-45884 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-45884 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-45884?: CVE-2021-45884 affects Brave. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-45884?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-45884 published?: CVE-2021-45884 was published on 2021-12-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:brave:brave:*:*:*:*:*:*:*:*

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