# CVE-2021-41140: Reactions leak for secure category topics and private messages

> Attackers can view reactions on secure topics and private messages, exposing user interactions. Discourse administrators should upgrade the plugin or disable it.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Oct 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-9358-hwg5-jrmh

## What is CVE-2021-41140?

CVE-2021-41140 is a medium-severity vulnerability in discourse-reactions, published on 19 Oct 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Discourse-reactions is a plugin for the Discourse platform that allows user to add their reactions to the post. In affected versions reactions given by user to secure topics and private messages are visible. This issue is patched in version 0.2 of discourse-reaction. Users who are unable to update are advised to disable the Discourse-reactions plugin in admin panel.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), CWE-668 (Exposure of Resource to Wrong Sphere)

## Which versions are affected by CVE-2021-41140?

It affects 1 product.


Products: Discourse Discourse Reactions.

## How do I fix CVE-2021-41140?

No fix has been published for CVE-2021-41140 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-41140 being exploited?

There is no known exploitation of CVE-2021-41140 in the wild and no public exploit code.

## Other vulnerabilities in discourse-reactions

- [CVE-2023-49098](https://insights.sbomify.com/CVE-2023-49098/): Reaction data for user notifications exposed in Discourse-reactions (low 3.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-41140 and fix it if it is affected.

What it is: CVE-2021-41140 is a medium-severity vulnerability in discourse-reactions, published on 19 Oct 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-41140 in the wild and no public exploit code.

Affected product: discourse-reactions. 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-2021-41140/ (Markdown: https://insights.sbomify.com/CVE-2021-41140/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-41140
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-41140
- OSV: https://osv.dev/vulnerability/CVE-2021-41140

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-41140/
Summaries are generated and may contain mistakes; the official description above is the record.