# CVE-2020-27735: Cross-site scripting in n/a

> An attacker can inject arbitrary HTML and JavaScript into Wing FTP help pages via crafted links, executing code in the user's browser.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **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:** 20 Jan 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-v47h-2vrq-3gqp

## What is CVE-2020-27735?

CVE-2020-27735 is a medium-severity cross-site scripting vulnerability in n/a, published on 20 Jan 2021. 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

An XSS issue was discovered in Wing FTP 6.4.4. An arbitrary IFRAME element can be included in the help pages via a crafted link, leading to the execution of (sandboxed) arbitrary HTML and JavaScript in the user's browser.

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

## Which versions are affected by CVE-2020-27735?

It affects 1 product.


Products: Wftpserver Wing Ftp Server.

## How do I fix CVE-2020-27735?

No fix has been published for CVE-2020-27735 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-27735 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-27735 exists.

Public exploit code:

- Wing FTP 6.4.4 - Cross-Site Scripting (nuclei): http/cves/2020/CVE-2020-27735.yaml

## Other vulnerabilities in n/a

- [CVE-2025-47812](https://insights.sbomify.com/CVE-2025-47812/): Wing FTP Server Improper Neutralization of Null Byte or NUL Character (critical 10.0, exploited in the wild)
- [CVE-2025-47813](https://insights.sbomify.com/CVE-2025-47813/): Wing FTP Server Information Disclosure (medium 4.3, exploited in the wild)
- [CVE-2026-44403](https://insights.sbomify.com/CVE-2026-44403/): Wing FTP Server < 8.1.3 Authenticated Remote Code Execution via Session Serialization (high 8.6)
- [CVE-2020-37032](https://insights.sbomify.com/CVE-2020-37032/): Wing FTP Server 6.3.8 - Remote Code Execution (high 8.6)
- [CVE-2019-25267](https://insights.sbomify.com/CVE-2019-25267/): Wing FTP Server 6.0.7 - Unquoted Service Path (high 8.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27735 and fix it if it is affected.

What it is: CVE-2020-27735 is a medium-severity cross-site scripting vulnerability in n/a, published on 20 Jan 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-27735 exists.

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-2020-27735/ (Markdown: https://insights.sbomify.com/CVE-2020-27735/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27735
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27735
- OSV: https://osv.dev/vulnerability/CVE-2020-27735

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-27735/
Summaries are generated and may contain mistakes; the official description above is the record.