# CVE-2021-24943: Registrations for the Events Calendar < 2.7.6 - Unauthenticated SQL Injection

> Unauthenticated attackers can inject SQL via the event_id parameter in the rtec_send_unregister_link AJAX action, allowing unauthorized database access.

- **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:** 6 Dec 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-756m-jgjv-8g68

## What is CVE-2021-24943?

CVE-2021-24943 is a critical SQL injection vulnerability in Unknown Registrations for the Events Calendar – Event Registration Plugin, published on 6 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Registrations for the Events Calendar WordPress plugin before 2.7.6 does not sanitise and escape the event_id in the rtec_send_unregister_link AJAX action (available to both unauthenticated and authenticated users) before using it in a SQL statement, leading to an unauthenticated SQL injection.

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

## Which versions are affected by CVE-2021-24943?

It affects 1 product.


Products: Roundupwp Registrations for the Events Calendar.

## How do I fix CVE-2021-24943?

No fix has been published for CVE-2021-24943 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-24943 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-24943 exists.

Public exploit code:

- Registrations for the Events Calendar < 2.7.6 - SQL Injection (nuclei): http/cves/2021/CVE-2021-24943.yaml

## Other vulnerabilities in Unknown Registrations for the Events Calendar – Event Registration Plugin

- [CVE-2024-7982](https://insights.sbomify.com/CVE-2024-7982/): Registrations for The Events Calendar < 2.12.4 - Unauthenticated Stored XSS (critical 9.6)
- [CVE-2024-39638](https://insights.sbomify.com/CVE-2024-39638/): WordPress Registrations for the Events Calendar plugin <= 2.12.2 - SQL Injection vulnerability (high 8.5)
- [CVE-2024-10703](https://insights.sbomify.com/CVE-2024-10703/): Registrations for The Events Calendar < 2.13.4 - Admin+ Stored XSS (medium 6.1)
- [CVE-2021-25083](https://insights.sbomify.com/CVE-2021-25083/): Registrations for the Events Calendar < 2.7.10 - Reflected Cross-Site Scripting (medium 6.1)
- [CVE-2021-24876](https://insights.sbomify.com/CVE-2021-24876/): Registrations for The Events Calendar < 2.7.5 - Reflected Cross-Site Scripting (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-24943 and fix it if it is affected.

What it is: CVE-2021-24943 is a critical SQL injection vulnerability in Unknown Registrations for the Events Calendar – Event Registration Plugin, published on 6 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-24943 exists.

Affected product: Unknown Registrations for the Events Calendar – Event Registration Plugin. 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-2021-24943/ (Markdown: https://insights.sbomify.com/CVE-2021-24943/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-24943
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-24943
- OSV: https://osv.dev/vulnerability/CVE-2021-24943

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-24943/
Summaries are generated and may contain mistakes; the official description above is the record.