# CVE-2021-32661: TechDocs object element script injection

> Attackers can inject malicious scripts via object elements in TechDocs, potentially stealing sensitive data from other users.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 3 Jun 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-gg96-f8wr-p89f

## What is CVE-2021-32661?

CVE-2021-32661 is a medium-severity cross-site scripting vulnerability in backstage, published on 3 Jun 2021. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Backstage is an open platform for building developer portals. In versions of Backstage's Techdocs Plugin (`@backstage/plugin-techdocs`) prior to 0.9.5, a malicious internal actor can potentially upload documentation content with malicious scripts by embedding the script within an `object` element. This may give access to sensitive data when other users visit that same documentation page. The ability to upload malicious content may be limited by internal code review processes, unless the chosen TechDocs deployment method is to use an object store and the actor has access to upload files directly to that store. The vulnerability is patched in the `0.9.5` release of `@backstage/plugin-techdocs`.

Weakness: CWE-434 (Unrestricted Upload of File with Dangerous Type), CWE-77 (Improper Neutralization of Special Elements used in a Command)

## Which versions are affected by CVE-2021-32661?

2 open source packages ship an affected version, including @backstage/plugin-techdocs. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@backstage/plugin-techdocs` | npm | All versions | 0.9.5 |
| `@backstage/plugin-techdocs` | npm | All versions | 0.9.5 |

Products: Linuxfoundation \@Backstage\/Plugin-Techdocs.

## How do I fix CVE-2021-32661?

Upgrade @backstage/plugin-techdocs to 0.9.5 or later.

## Is CVE-2021-32661 being exploited?

There is no known exploitation of CVE-2021-32661 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-32661 and fix it if it is affected.

What it is: CVE-2021-32661 is a medium-severity cross-site scripting vulnerability in backstage, published on 3 Jun 2021. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-32661 in the wild and no public exploit code.

Affected packages and fixed versions:
- @backstage/plugin-techdocs (npm): affected all versions; fixed in 0.9.5
- @backstage/plugin-techdocs (npm): affected all versions; fixed in 0.9.5

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-2021-32661/ (Markdown: https://insights.sbomify.com/CVE-2021-32661/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-32661
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-32661
- OSV: https://osv.dev/vulnerability/CVE-2021-32661

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-32661/
Summaries are generated and may contain mistakes; the official description above is the record.