# CVE-2022-29166: Improper handling of multiline messages in matrix-appservice-irc

> An attacker can trick Matrix users into executing arbitrary IRC commands by replying to maliciously crafted messages in bridged rooms.

- **Severity:** High 8.0 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 5 May 2022
- **Updated:** 23 Apr 2025
- **Also known as:** GHSA-37hr-348p-rmf4

## What is CVE-2022-29166?

CVE-2022-29166 is a high-severity command injection vulnerability in matrix-org matrix-appservice-irc, published on 5 May 2022. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

matrix-appservice-irc is a Node.js IRC bridge for Matrix. The vulnerability in node-irc allows an attacker to manipulate a Matrix user into executing IRC commands by having them reply to a maliciously crafted message. The vulnerability has been patched in matrix-appservice-irc 0.33.2. Refrain from replying to messages from untrusted participants in IRC-bridged Matrix rooms. There are no known workarounds for this issue.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2022-29166?

2 open source packages ship an affected version, including matrix-appservice-irc. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `matrix-appservice-irc` | npm | All versions | 0.33.2 |
| `matrix-appservice-irc` | npm | All versions | 0.33.2 |

Products: Matrix Matrix Irc Bridge.

## How do I fix CVE-2022-29166?

Upgrade matrix-appservice-irc to 0.33.2 or later.

## Is CVE-2022-29166 being exploited?

There is no known exploitation of CVE-2022-29166 in the wild and no public exploit code.

## Other vulnerabilities in matrix-org matrix-appservice-irc

- [CVE-2022-39203](https://insights.sbomify.com/CVE-2022-39203/): Parsing issue in matrix-org/node-irc leading to room takeovers (high 8.8)
- [CVE-2023-38690](https://insights.sbomify.com/CVE-2023-38690/): matrix-appservice-irc IRC command injection via admin commands containing newlines (medium 5.8)
- [CVE-2022-3971](https://insights.sbomify.com/CVE-2022-3971/): matrix-appservice-irc PgDataStore.ts sql injection (medium 4.6)
- [CVE-2022-39202](https://insights.sbomify.com/CVE-2022-39202/): IRC mode parameter confusion in matrix-appservice-irc (medium 4.3)
- [CVE-2023-38700](https://insights.sbomify.com/CVE-2023-38700/): matrix-appservice-irc events can be crafted to leak parts of targeted messages from other bridged rooms (low 3.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-29166 and fix it if it is affected.

What it is: CVE-2022-29166 is a high-severity command injection vulnerability in matrix-org matrix-appservice-irc, published on 5 May 2022. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2022-29166 in the wild and no public exploit code.

Affected packages and fixed versions:
- matrix-appservice-irc (npm): affected all versions; fixed in 0.33.2
- matrix-appservice-irc (npm): affected all versions; fixed in 0.33.2

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-2022-29166/ (Markdown: https://insights.sbomify.com/CVE-2022-29166/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-29166
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-29166
- OSV: https://osv.dev/vulnerability/CVE-2022-29166

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-29166/
Summaries are generated and may contain mistakes; the official description above is the record.