# CVE-2023-38700: matrix-appservice-irc events can be crafted to leak parts of targeted messages from other bridged rooms

> Attackers can craft events to leak parts of targeted messages from other bridged rooms in the Matrix IRC bridge.

- **Severity:** Low 3.5 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Aug 2023
- **Updated:** 3 Oct 2024
- **Also known as:** GHSA-c7hh-3v6c-fj4q

## What is CVE-2023-38700?

CVE-2023-38700 is a low-severity vulnerability in matrix-org matrix-appservice-irc, published on 4 Aug 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

matrix-appservice-irc is a Node.js IRC bridge for Matrix. Prior to version 1.0.1, it was possible to craft an event such that it would leak part of a targeted message event from another bridged room. This required knowing an event ID to target. Version 1.0.1n fixes this issue. As a workaround, set the `matrixHandler.eventCacheSize` config value to `0`. This workaround may impact performance.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2023-38700?

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 | 1.0.1 |
| `matrix-appservice-irc` | npm | All versions | 1.0.1 |

Products: Matrix Matrix Irc Bridge.

## How do I fix CVE-2023-38700?

Upgrade matrix-appservice-irc to 1.0.1 or later.

## Is CVE-2023-38700 being exploited?

There is no known exploitation of CVE-2023-38700 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-2022-29166](https://insights.sbomify.com/CVE-2022-29166/): Improper handling of multiline messages in matrix-appservice-irc (high 8.0)
- [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)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-38700 and fix it if it is affected.

What it is: CVE-2023-38700 is a low-severity vulnerability in matrix-org matrix-appservice-irc, published on 4 Aug 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-38700 in the wild and no public exploit code.

Affected packages and fixed versions:
- matrix-appservice-irc (npm): affected all versions; fixed in 1.0.1
- matrix-appservice-irc (npm): affected all versions; fixed in 1.0.1

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-2023-38700/ (Markdown: https://insights.sbomify.com/CVE-2023-38700/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-38700
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-38700
- OSV: https://osv.dev/vulnerability/CVE-2023-38700

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-38700/
Summaries are generated and may contain mistakes; the official description above is the record.