# CVE-2021-35976: Cross-site scripting in n/a

> Reflected XSS in Plesk site preview allows attackers to execute JavaScript in victims' browsers without authentication.

- **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:** 10 Sep 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-55cx-26p7-7qcw

## What is CVE-2021-35976?

CVE-2021-35976 is a medium-severity cross-site scripting vulnerability in n/a, published on 10 Sep 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

The feature to preview a website in Plesk Obsidian 18.0.0 through 18.0.32 on Linux is vulnerable to reflected XSS via the /plesk-site-preview/ PATH, aka PFSI-62467. The attacker could execute JavaScript code in the victim's browser by using the link to preview sites hosted on the server. Authentication is not required to exploit the vulnerability.

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

## Which versions are affected by CVE-2021-35976?

It affects 1 product.


Products: Plesk Obsidian.

## How do I fix CVE-2021-35976?

No fix has been published for CVE-2021-35976 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-35976 being exploited?

There is no known exploitation of CVE-2021-35976 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2022-45130](https://insights.sbomify.com/CVE-2022-45130/): Cross-site request forgery in n/a (medium 6.5)
- [CVE-2023-24044](https://insights.sbomify.com/CVE-2023-24044/): Open redirect in n/a (medium 6.1)
- [CVE-2020-11583](https://insights.sbomify.com/CVE-2020-11583/): Cross-site scripting in n/a (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-35976 and fix it if it is affected.

What it is: CVE-2021-35976 is a medium-severity cross-site scripting vulnerability in n/a, published on 10 Sep 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-2021-35976 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-2021-35976/ (Markdown: https://insights.sbomify.com/CVE-2021-35976/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-35976
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-35976
- OSV: https://osv.dev/vulnerability/CVE-2021-35976

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-35976/
Summaries are generated and may contain mistakes; the official description above is the record.