# CVE-2019-16521: Cross-site scripting in n/a

> Reflected XSS in Broken Link Checker allows attackers to execute scripts via crafted GET parameters, affecting end-of-life WordPress installations.

- **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:** No
- **Published:** 16 Oct 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-48cc-3r5m-2jp3

## What is CVE-2019-16521?

CVE-2019-16521 is a medium-severity cross-site scripting vulnerability in n/a, published on 16 Oct 2019. 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

The broken-link-checker plugin through 1.11.8 for WordPress (aka Broken Link Checker) is susceptible to Reflected XSS due to improper encoding and insertion of an HTTP GET parameter into HTML. The filter function on the page listing all detected broken links can be exploited by providing an XSS payload in the s_filter GET parameter in a filter_id=search request. NOTE: this is an end-of-life product.

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

## Which versions are affected by CVE-2019-16521?

It affects 1 product.


Products: Managewp Broken Link Checker.

## How do I fix CVE-2019-16521?

No fix has been published for CVE-2019-16521 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-16521 being exploited?

There is no known exploitation of CVE-2019-16521 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2023-23737](https://insights.sbomify.com/CVE-2023-23737/): WordPress MainWP Broken Links Checker Extension Plugin <= 4.0 is vulnerable to SQL Injection (critical 9.3)
- [CVE-2022-2438](https://insights.sbomify.com/CVE-2022-2438/): Broken Link Checker <= 1.11.16 - Authenticated (Admin+) PHAR Deserialization (high 7.2)
- [CVE-2019-17207](https://insights.sbomify.com/CVE-2019-17207/): Cross-site scripting in n/a (medium 5.4)
- [CVE-2022-3922](https://insights.sbomify.com/CVE-2022-3922/): Broken Link Checker < 1.11.20 - Admin+ Cross-Site Scripting (medium 4.8)
- [CVE-2024-10903](https://insights.sbomify.com/CVE-2024-10903/): Broken Link Checker < 2.4.2 - Admin+ SSRF (medium 4.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-16521 and fix it if it is affected.

What it is: CVE-2019-16521 is a medium-severity cross-site scripting vulnerability in n/a, published on 16 Oct 2019. 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-2019-16521 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-2019-16521/ (Markdown: https://insights.sbomify.com/CVE-2019-16521/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-16521
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-16521
- OSV: https://osv.dev/vulnerability/CVE-2019-16521

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-16521/
Summaries are generated and may contain mistakes; the official description above is the record.