# CVE-2021-24252: Event Banner <= 1.3 - Arbitrary File Upload to RCE

> Admins can upload arbitrary executable files leading to remote code execution, or attackers can exploit CSRF/LFI vectors to achieve the same result.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 May 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-4r26-734p-358q

## What is CVE-2021-24252?

CVE-2021-24252 is a high-severity vulnerability in Unknown Event Banner, published on 5 May 2021. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

The Event Banner WordPress plugin through 1.3 does not verify the uploaded image file, allowing admin accounts to upload arbitrary files, such as .exe, .php, or others executable, leading to RCE. Due to the lack of CSRF check, the issue can also be used via such vector to achieve the same result, or via a LFI as authorisation checks are missing (but would require WP to be loaded)

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type)

## Which versions are affected by CVE-2021-24252?

It affects 1 product.


Products: Wp-Eventmanager Event Banner.

## How do I fix CVE-2021-24252?

No fix has been published for CVE-2021-24252 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-24252 being exploited?

There is no known exploitation of CVE-2021-24252 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-24252 and fix it if it is affected.

What it is: CVE-2021-24252 is a high-severity vulnerability in Unknown Event Banner, published on 5 May 2021. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-24252 in the wild and no public exploit code.

Affected product: Unknown Event Banner. 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-2021-24252/ (Markdown: https://insights.sbomify.com/CVE-2021-24252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-24252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-24252
- OSV: https://osv.dev/vulnerability/CVE-2021-24252

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-24252/
Summaries are generated and may contain mistakes; the official description above is the record.