# CVE-2021-41563: Tad Book3 - Stored XSS

> Unauthenticated attackers can inject JavaScript into the book editing function, leading to stored XSS attacks.

- **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:** 8 Oct 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-6p96-35cj-r28v

## What is CVE-2021-41563?

CVE-2021-41563 is a medium-severity cross-site scripting vulnerability in Tad Book3, published on 8 Oct 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

Tad Book3 editing book function does not filter special characters. Unauthenticated attackers can remotely inject JavaScript syntax and execute stored XSS attacks.

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

## Which versions are affected by CVE-2021-41563?

It affects 1 product.


Products: Tad Book3 Project Tad Book3.

## How do I fix CVE-2021-41563?

No fix has been published for CVE-2021-41563 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-41563 being exploited?

There is no known exploitation of CVE-2021-41563 in the wild and no public exploit code.

## Other vulnerabilities in Tad Book3

- [CVE-2021-41974](https://insights.sbomify.com/CVE-2021-41974/): Tad Book3 - Improper Authorization (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-41563 and fix it if it is affected.

What it is: CVE-2021-41563 is a medium-severity cross-site scripting vulnerability in Tad Book3, published on 8 Oct 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-2021-41563 in the wild and no public exploit code.

Affected product: Tad Book3. 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-2021-41563/ (Markdown: https://insights.sbomify.com/CVE-2021-41563/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-41563
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-41563
- OSV: https://osv.dev/vulnerability/CVE-2021-41563

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-41563/
Summaries are generated and may contain mistakes; the official description above is the record.