# CVE-2021-44543: Cross-site scripting in privoxy

> An XSS vulnerability in Privoxy allows attackers to execute scripts when the user-manual is served, requiring specific configuration.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 23 Dec 2021
- **Updated:** 4 Aug 2024
- **Also known as:** ALPINE-CVE-2021-44543, DEBIAN-CVE-2021-44543, GHSA-hf3j-m5fx-q82c, UBUNTU-CVE-2021-44543

## What is CVE-2021-44543?

CVE-2021-44543 is a medium-severity cross-site scripting vulnerability in privoxy, published on 23 Dec 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

An XSS vulnerability was found in Privoxy which was fixed in cgi_error_no_template() by encode the template name when Privoxy is configured to servce the user-manual itself.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2021-44543?

It affects 1 product.


Products: Privoxy Privoxy.

## How do I fix CVE-2021-44543?

Apply the vendor's patch.

## Is CVE-2021-44543 being exploited?

There is no known exploitation of CVE-2021-44543 in the wild and no public exploit code.

## Other vulnerabilities in privoxy

- [CVE-2019-3699](https://insights.sbomify.com/CVE-2019-3699/): Local privilege escalation from user privoxy to root (high 7.7)
- [CVE-2021-44540](https://insights.sbomify.com/CVE-2021-44540/): Denial of service in Privoxy (high 7.5)
- [CVE-2021-44541](https://insights.sbomify.com/CVE-2021-44541/): Denial of service in Privoxy (high 7.5)
- [CVE-2021-44542](https://insights.sbomify.com/CVE-2021-44542/): Denial of service in Privoxy (high 7.5)
- [CVE-2021-20209](https://insights.sbomify.com/CVE-2021-20209/): Denial of service in privoxy (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-44543 and fix it if it is affected.

What it is: CVE-2021-44543 is a medium-severity cross-site scripting vulnerability in privoxy, published on 23 Dec 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-44543 in the wild and no public exploit code.

Affected product: privoxy. 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-2021-44543/ (Markdown: https://insights.sbomify.com/CVE-2021-44543/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-44543
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-44543
- OSV: https://osv.dev/vulnerability/CVE-2021-44543

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-44543/
Summaries are generated and may contain mistakes; the official description above is the record.