# CVE-2021-40909: Cross-site scripting in n/a

> Remote attackers can execute arbitrary code via XSS in the first_name, last_name, and email parameters of this PHP CRUD application.

- **Severity:** Critical 9.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 24 Jan 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-vqxh-g4gf-cp2w

## What is CVE-2021-40909?

CVE-2021-40909 is a critical cross-site scripting vulnerability in n/a, published on 24 Jan 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Cross site scripting (XSS) vulnerability in sourcecodester PHP CRUD without Refresh/Reload using Ajax and DataTables Tutorial v1 by oretnom23, allows remote attackers to execute arbitrary code via the first_name, last_name, and email parameters to /ajax_crud.

Weakness: CWE-89 (Improper Neutralization of Special Elements used in an SQL Command), CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2021-40909?

It affects 1 product.


Products: Php Crud Without Refresh\/Reload Using Ajax and Datatables Tutorial Project Php Crud Without Refresh\/Reload Using Ajax and Datatables Tutorial.

## How do I fix CVE-2021-40909?

No fix has been published for CVE-2021-40909 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-40909 being exploited?

There is no known exploitation of CVE-2021-40909 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-40909 and fix it if it is affected.

What it is: CVE-2021-40909 is a critical cross-site scripting vulnerability in n/a, published on 24 Jan 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-40909 in the wild and no public exploit code.

Affected product: n/a. 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-2021-40909/ (Markdown: https://insights.sbomify.com/CVE-2021-40909/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-40909
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-40909
- OSV: https://osv.dev/vulnerability/CVE-2021-40909

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-40909/
Summaries are generated and may contain mistakes; the official description above is the record.