# CVE-2020-29240: Cross-site scripting in n/a

> An attacker can inject XSS payloads into the URL field, triggering execution when an admin views the Pages Overview section.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 2 Dec 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-gx4g-83m8-7hhx

## What is CVE-2020-29240?

CVE-2020-29240 is a medium-severity cross-site scripting vulnerability in n/a, published on 2 Dec 2020. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Lepton-CMS 4.7.0 is affected by cross-site scripting (XSS). An attacker can inject the XSS payload in the URL field of the admin page and each time an admin visits the Menu-Pages-Pages Overview section, the XSS will be triggered.

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

## Which versions are affected by CVE-2020-29240?

It affects 1 product.


Products: Lepton-Cms Leptoncms.

## How do I fix CVE-2020-29240?

No fix has been published for CVE-2020-29240 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-29240 being exploited?

There is no known exploitation of CVE-2020-29240 in the wild and no public exploit code.

Public exploit code:

- LEPTON CMS 4.7.0 - 'URL' Persistent Cross-Site Scripting (exploitdb)

## Other vulnerabilities in n/a

- [CVE-2025-56704](https://insights.sbomify.com/CVE-2025-56704/): File upload in n/a (high 8.8)
- [CVE-2024-29514](https://insights.sbomify.com/CVE-2024-29514/): File upload in n/a (high 8.8)
- [CVE-2024-29515](https://insights.sbomify.com/CVE-2024-29515/): File upload in n/a (high 8.8)
- [CVE-2024-24520](https://insights.sbomify.com/CVE-2024-24520/): Code injection in n/a (high 7.8)
- [CVE-2024-24399](https://insights.sbomify.com/CVE-2024-24399/): File upload in n/a (high 7.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-29240 and fix it if it is affected.

What it is: CVE-2020-29240 is a medium-severity cross-site scripting vulnerability in n/a, published on 2 Dec 2020. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-29240 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-2020-29240/ (Markdown: https://insights.sbomify.com/CVE-2020-29240/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-29240
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-29240
- OSV: https://osv.dev/vulnerability/CVE-2020-29240

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-29240/
Summaries are generated and may contain mistakes; the official description above is the record.