# CVE-2021-25983: FactorJS - Reflected Cross-Site Scripting (XSS) in Tags and Categories Functionality

> An unauthenticated attacker can execute malicious JavaScript via reflected XSS in the FactorJS forum plugin to steal session cookies.

- **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:** 16 Nov 2021
- **Updated:** 30 Apr 2025
- **Also known as:** GHSA-xfqr-hhpm-c4xx

## What is CVE-2021-25983?

CVE-2021-25983 is a medium-severity cross-site scripting vulnerability in FactorJS Factor, published on 16 Nov 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

In Factor (App Framework & Headless CMS) forum plugin, versions v1.3.8 to v1.8.30, are vulnerable to reflected Cross-Site Scripting (XSS) at the “tags” and “category” parameters in the URL. An unauthenticated attacker can execute malicious JavaScript code and steal the session cookies.

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

## Which versions are affected by CVE-2021-25983?

It affects 1 product.


Products: Darwin Factor.

## How do I fix CVE-2021-25983?

No fix has been published for CVE-2021-25983 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-25983 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-25983 exists.

## Other vulnerabilities in FactorJS Factor

- [CVE-2021-25985](https://insights.sbomify.com/CVE-2021-25985/): FactorJS - Insufficient Session Expiration Leads to a Local Account Takeover (high 7.8)
- [CVE-2021-25982](https://insights.sbomify.com/CVE-2021-25982/): FactorJS - Reflected Cross-Site Scripting (XSS) in Search Functionality (medium 6.1)
- [CVE-2021-25984](https://insights.sbomify.com/CVE-2021-25984/): FactorJS - Stored Cross-Site Scripting (XSS) in Post Reply Functionality (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-25983 and fix it if it is affected.

What it is: CVE-2021-25983 is a medium-severity cross-site scripting vulnerability in FactorJS Factor, published on 16 Nov 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-2021-25983 exists.

Affected product: FactorJS Factor. 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-2021-25983/ (Markdown: https://insights.sbomify.com/CVE-2021-25983/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-25983
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-25983
- OSV: https://osv.dev/vulnerability/CVE-2021-25983

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-25983/
Summaries are generated and may contain mistakes; the official description above is the record.