# GHSA-hfxh-rjv7-2369: Uptime Kuma Authenticated remote code execution via TailscalePing

> Authenticated users can execute arbitrary commands on the server via command injection in the Tailscale Ping monitor feature.

- **Severity:** Not scored
- **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:** 27 Nov 2023

## What is GHSA-hfxh-rjv7-2369?

GHSA-hfxh-rjv7-2369 is a command injection vulnerability in uptime-kuma, published on 27 Nov 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

### Summary

The `runTailscalePing` method of the `TailscalePing` class injects the `hostname` parameter inside a shell command, leading to a command injection and the possibility to run arbitrary commands on the server.

### Details

When adding a new monitor on Uptime Kuma, we can select the "Tailscale Ping" type. Then we can add a hostname and insert a command injection payload into it. The front-end application requires that the field follow a specific pattern, this validation only happens on the front-end and can be removed by removing the attribute `pattern` on the `input` element.

https://github.com/louislam/uptime-kuma/blob/dc4242019331e65a79ac16deef97510144e01b12/server/monitor-types/tailscale-ping.js#L40-L46

We can finally add the new monitor and observe that our command is being executed.

**NOTE:** When using Uptime Kuma inside a container, the "TailScale Ping" type is not visible. We can fake this information by intercepting WebSocket messages and set the `isContainer` option to `false`.

### PoC

* Authenticate.
* Create a new monitor.
* Select the TailScale Ping type (if not visible, see the note in the details section).
* Insert the command injection payload inside the `hostname` field. (for example `$(id >&2)`)
* Remove the `pattern` requirement on the field.
* Save and start the monitor.

### Impact

An authenticated user can execute arbitrary command on the server running Uptime Kuma.

### Remediation

There are other command execution in the codebase, they use a method `spawn` from the `child_process` module which does not interpret the command as a shell command, the same thing should be done here.

**NOTE:** The Tailscale CLI seems to support the `--` sequence. It should be used between the `ping` subcommand and the `hostname` argument to avoid argument injection.

## Which versions are affected by GHSA-hfxh-rjv7-2369?

2 open source packages ship an affected version, including uptime-kuma.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `uptime-kuma` | npm | From 1.23.0 | 1.23.7 |
| `uptime-kuma` | npm | From 1.23.0 | 1.23.7 |

## How do I fix GHSA-hfxh-rjv7-2369?

Upgrade uptime-kuma to 1.23.7 or later.

## Is GHSA-hfxh-rjv7-2369 being exploited?

There is no known exploitation of GHSA-hfxh-rjv7-2369 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-hfxh-rjv7-2369 and fix it if it is affected.

What it is: GHSA-hfxh-rjv7-2369 is a command injection vulnerability in uptime-kuma, published on 27 Nov 2023. 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 GHSA-hfxh-rjv7-2369 in the wild and no public exploit code.

Affected packages and fixed versions:
- uptime-kuma (npm): affected from 1.23.0; fixed in 1.23.7
- uptime-kuma (npm): affected from 1.23.0; fixed in 1.23.7

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/GHSA-hfxh-rjv7-2369/ (Markdown: https://insights.sbomify.com/GHSA-hfxh-rjv7-2369/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-hfxh-rjv7-2369

---
From sbomify Insights: https://insights.sbomify.com/GHSA-hfxh-rjv7-2369/
Summaries are generated and may contain mistakes; the official description above is the record.