# CVE-2021-24562: LifterLMS < 4.21.2 - Access Other Student Grades/Answers via IDOR

> Students can view other students' answers and grades due to an Insecure Direct Object Reference vulnerability in the LifterLMS plugin.

- **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:** 23 Aug 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-h388-6737-2grv

## What is CVE-2021-24562?

CVE-2021-24562 is a high-severity missing authorization vulnerability in Unknown LMS by LifterLMS – Online Course, Membership & Learning Management System Plugin for WordPress, published on 23 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The LMS by LifterLMS – Online Course, Membership & Learning Management System Plugin for WordPress plugin before 4.21.2 was affected by an IDOR issue, allowing students to see other student answers and grades

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2021-24562?

It affects 1 product.


Products: Lifterlms Lifterlms.

## How do I fix CVE-2021-24562?

No fix has been published for CVE-2021-24562 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-24562 being exploited?

There is no known exploitation of CVE-2021-24562 in the wild and no public exploit code.

## Other vulnerabilities in Unknown LMS by LifterLMS – Online Course, Membership & Learning Management System Plugin for WordPress

- [CVE-2020-6008](https://insights.sbomify.com/CVE-2020-6008/): File upload in LifterLMS Wordpress Plugin (critical 9.8)
- [CVE-2019-15896](https://insights.sbomify.com/CVE-2019-15896/): Missing authorization in n/a (critical 9.8)
- [CVE-2025-52717](https://insights.sbomify.com/CVE-2025-52717/): WordPress LifterLMS plugin <= 8.0.6 - SQL Injection Vulnerability (critical 9.3)
- [CVE-2024-4743](https://insights.sbomify.com/CVE-2024-4743/): LifterLMS – WordPress LMS Plugin for eLearning <= 7.6.2 - Authenticated (Contributor+) SQL Injection via Shortcode (high 8.8)
- [CVE-2024-7349](https://insights.sbomify.com/CVE-2024-7349/): LifterLMS <= 7.7.5 - Authenticated (Admin+) SQL Injection (high 7.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-24562 and fix it if it is affected.

What it is: CVE-2021-24562 is a high-severity missing authorization vulnerability in Unknown LMS by LifterLMS – Online Course, Membership & Learning Management System Plugin for WordPress, published on 23 Aug 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-2021-24562 in the wild and no public exploit code.

Affected product: Unknown LMS by LifterLMS – Online Course, Membership & Learning Management System Plugin for WordPress. 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-2021-24562/ (Markdown: https://insights.sbomify.com/CVE-2021-24562/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-24562
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-24562
- OSV: https://osv.dev/vulnerability/CVE-2021-24562

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-24562/
Summaries are generated and may contain mistakes; the official description above is the record.