# CVE-2021-20116: Cross-site scripting in TCExam

> Reflected XSS in TCExam allows attackers to hijack administrator sessions or perform actions on their behalf via malicious links.

- **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:** 5 Aug 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-wghf-896v-rpqj

## What is CVE-2021-20116?

CVE-2021-20116 is a medium-severity cross-site scripting vulnerability in TCExam, published on 5 Aug 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

A reflected cross-site scripting vulnerability exists in TCExam <= 14.8.4. The paths provided in the f, d, and dir parameters in tce_select_mediafile.php were not properly validated and could cause reflected XSS via the unsanitized output of the path supplied. An attacker could craft a malicious link which, if triggered by an administrator, could result in the attacker hijacking the victim's session or performing actions on their behalf.

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

## Which versions are affected by CVE-2021-20116?

It affects 1 product.


Products: Tecnick Tcexam.

## How do I fix CVE-2021-20116?

No fix has been published for CVE-2021-20116 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-20116 being exploited?

There is no known exploitation of CVE-2021-20116 in the wild and no public exploit code.

## Other vulnerabilities in TCExam

- [CVE-2021-20114](https://insights.sbomify.com/CVE-2021-20114/): Information disclosure in TCExam (high 7.5)
- [CVE-2020-5745](https://insights.sbomify.com/CVE-2020-5745/): Cross-site request forgery in TCExam (high 7.4)
- [CVE-2012-4237](https://insights.sbomify.com/CVE-2012-4237/): SQL injection in n/a (medium 6.8)
- [CVE-2010-2153](https://insights.sbomify.com/CVE-2010-2153/): File upload in n/a (medium 6.8)
- [CVE-2023-6554](https://insights.sbomify.com/CVE-2023-6554/): Missing authorisation in TCExam (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-20116 and fix it if it is affected.

What it is: CVE-2021-20116 is a medium-severity cross-site scripting vulnerability in TCExam, published on 5 Aug 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-2021-20116 in the wild and no public exploit code.

Affected product: TCExam. 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-2021-20116/ (Markdown: https://insights.sbomify.com/CVE-2021-20116/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-20116
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-20116
- OSV: https://osv.dev/vulnerability/CVE-2021-20116

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-20116/
Summaries are generated and may contain mistakes; the official description above is the record.