# CVE-2021-24751: GenerateBlocks < 1.4.0 - Contributor+ Stored Cross-Site Scripting

> Contributors can inject malicious scripts via the container block's tagName attribute, allowing attackers to execute code in victim browsers.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 29 Nov 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-f648-43x4-7j96

## What is CVE-2021-24751?

CVE-2021-24751 is a medium-severity cross-site scripting vulnerability in Unknown GenerateBlocks, published on 29 Nov 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

The GenerateBlocks WordPress plugin before 1.4.0 does not validate the generateblocks/container block's tagName attribute, which could allow users with a role as low as contributor to perform Cross-Site Scripting attacks.

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

## Which versions are affected by CVE-2021-24751?

It affects 1 product.


Products: Generateblocks Generateblocks.

## How do I fix CVE-2021-24751?

No fix has been published for CVE-2021-24751 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-24751 being exploited?

There is no known exploitation of CVE-2021-24751 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-24751 and fix it if it is affected.

What it is: CVE-2021-24751 is a medium-severity cross-site scripting vulnerability in Unknown GenerateBlocks, published on 29 Nov 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-24751 in the wild and no public exploit code.

Affected product: Unknown GenerateBlocks. 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-2021-24751/ (Markdown: https://insights.sbomify.com/CVE-2021-24751/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-24751
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-24751
- OSV: https://osv.dev/vulnerability/CVE-2021-24751

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-24751/
Summaries are generated and may contain mistakes; the official description above is the record.