# CVE-2021-31761: Cross-site scripting in n/a

> Reflected XSS in Webmin allows attackers to execute remote commands via the running process feature, potentially leading to full system compromise.

- **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:** 25 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-v8w5-257f-g592

## What is CVE-2021-31761?

CVE-2021-31761 is a critical cross-site scripting vulnerability in Webmin Webmin, published on 25 Apr 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

Webmin 1.973 is affected by reflected Cross Site Scripting (XSS) to achieve Remote Command Execution through Webmin's running process feature.

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

## Which versions are affected by CVE-2021-31761?

It affects 1 product.


Products: Webmin Webmin.

## How do I fix CVE-2021-31761?

No fix has been published for CVE-2021-31761 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-31761 being exploited?

There is no known exploitation of CVE-2021-31761 in the wild and no public exploit code.

Public exploit code:

- Exploiting a Reflected Cross-Site Scripting (XSS) attack to get a Remote Command Execution (RCE) through the Webmin's running process feature (github_poc): https://github.com/Mesh3l911/CVE-2021-31761
- Exploiting a Reflected Cross-Site Scripting (XSS) attack to get a Remote Command Execution (RCE) through the Webmin's running process feature (github_poc): https://github.com/electronicbots/CVE-2021-31761
- Webmin 1.973 - 'run.cgi' Cross-Site Request Forgery (CSRF) (exploitdb)

## Other vulnerabilities in Webmin Webmin

- [CVE-2019-15107](https://insights.sbomify.com/CVE-2019-15107/): Webmin Command Injection (critical 9.8, exploited in the wild)
- [CVE-2002-2201](https://insights.sbomify.com/CVE-2002-2201/): Command injection in n/a (critical 10.0)
- [CVE-2001-1196](https://insights.sbomify.com/CVE-2001-1196/): Path traversal in n/a (critical 10.0)
- [CVE-2024-12828](https://insights.sbomify.com/CVE-2024-12828/): Webmin CGI Command Injection Remote Code Execution Vulnerability (critical 9.9)
- [CVE-2022-36446](https://insights.sbomify.com/CVE-2022-36446/): Cross-site scripting in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-31761 and fix it if it is affected.

What it is: CVE-2021-31761 is a critical cross-site scripting vulnerability in Webmin Webmin, published on 25 Apr 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: There is no known exploitation of CVE-2021-31761 in the wild and no public exploit code.

Affected product: Webmin Webmin. 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-2021-31761/ (Markdown: https://insights.sbomify.com/CVE-2021-31761/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-31761
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-31761
- OSV: https://osv.dev/vulnerability/CVE-2021-31761

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-31761/
Summaries are generated and may contain mistakes; the official description above is the record.