# CVE-2021-4340: uListing <= 1.6.6 - Unauthenticated SQL Injection

> Unauthenticated attackers can exploit SQL injection in the uListing WordPress plugin to extract sensitive database information.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Jun 2023
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-hv43-fjj6-p6qh

## What is CVE-2021-4340?

CVE-2021-4340 is a critical SQL injection vulnerability in stylemix Directory Listings WordPress plugin – uListing, published on 7 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The uListing plugin for WordPress is vulnerable to generic SQL Injection via the ‘listing_id’ parameter in versions up to, and including, 1.6.6 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query.  This makes it possible for unauthenticated attackers to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.

Weakness: CWE-89 (Improper Neutralization of Special Elements used in an SQL Command)

## Which versions are affected by CVE-2021-4340?

It affects 1 product.


Products: Stylemixthemes Ulisting.

## How do I fix CVE-2021-4340?

No fix has been published for CVE-2021-4340 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-4340 being exploited?

There is no known exploitation of CVE-2021-4340 in the wild and no public exploit code.

## Other vulnerabilities in stylemix Directory Listings WordPress plugin – uListing

- [CVE-2021-4341](https://insights.sbomify.com/CVE-2021-4341/): uListing <= 1.6.6 - Unauthenticated Wordpress Options Changes via AJAX (critical 9.8)
- [CVE-2021-4343](https://insights.sbomify.com/CVE-2021-4343/): uListing <= 1.6.6 - Unauthenticated Arbitrary Account Creation (critical 9.8)
- [CVE-2021-4346](https://insights.sbomify.com/CVE-2021-4346/): uListing <= 1.6.6 - Unauthenticated Arbitrary Account Changes (critical 9.8)
- [CVE-2021-4370](https://insights.sbomify.com/CVE-2021-4370/): uListing <= 1.6.6 - Missing Authorization (critical 9.8)
- [CVE-2021-4381](https://insights.sbomify.com/CVE-2021-4381/): uListing <= 1.6.6 - Unauthenticated Options Changes via wp_route (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-4340 and fix it if it is affected.

What it is: CVE-2021-4340 is a critical SQL injection vulnerability in stylemix Directory Listings WordPress plugin – uListing, published on 7 Jun 2023. 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-2021-4340 in the wild and no public exploit code.

Affected product: stylemix Directory Listings WordPress plugin – uListing. 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-2021-4340/ (Markdown: https://insights.sbomify.com/CVE-2021-4340/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-4340
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-4340
- OSV: https://osv.dev/vulnerability/CVE-2021-4340

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-4340/
Summaries are generated and may contain mistakes; the official description above is the record.