# CVE-2021-45884: Information disclosure in n/a

> Attackers can leak DNS requests outside the proxy when specific adblocking and proxy settings are enabled, exposing user browsing activity.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Dec 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-7q5w-r799-frgq

## What is CVE-2021-45884?

CVE-2021-45884 is a high-severity vulnerability in n/a, published on 27 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2021-45884?

It affects 1 product.


Products: Brave Brave.

## How do I fix CVE-2021-45884?

No fix has been published for CVE-2021-45884 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-45884 being exploited?

There is no known exploitation of CVE-2021-45884 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2022-47932](https://insights.sbomify.com/CVE-2022-47932/): Denial of service in n/a (medium 6.5)
- [CVE-2022-47933](https://insights.sbomify.com/CVE-2022-47933/): Denial of service in n/a (medium 6.5)
- [CVE-2022-47934](https://insights.sbomify.com/CVE-2022-47934/): Denial of service in n/a (medium 6.5)
- [CVE-2018-10798](https://insights.sbomify.com/CVE-2018-10798/): Denial of service in n/a (medium 6.5)
- [CVE-2018-10799](https://insights.sbomify.com/CVE-2018-10799/): Denial of service in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-45884 and fix it if it is affected.

What it is: CVE-2021-45884 is a high-severity vulnerability in n/a, published on 27 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-45884 in the wild and no public exploit code.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-45884/ (Markdown: https://insights.sbomify.com/CVE-2021-45884/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-45884
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-45884
- OSV: https://osv.dev/vulnerability/CVE-2021-45884

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-45884/
Summaries are generated and may contain mistakes; the official description above is the record.