CVE-2025-49070

Executive Summary

CVE-2025-49070 is a critical PHP Local File Inclusion (LFI) vulnerability in the Elessi WordPress theme developed by NasaTheme. The flaw resides in improper control of filenames used in PHP include/require statements, allowing an unauthenticated attacker to read arbitrary files from the server’s filesystem. This can lead to exposure of sensitive configuration files, database credentials, and source code. The vulnerability affects all versions of the Elessi theme prior to 6.4.1. No public exploit code or proof-of-concept is currently available, but the risk is elevated due to the lack of a vendor patch and the widespread use of WordPress.

Supply Chain & Package Security

This vulnerability is specific to the WordPress ecosystem and the Elessi theme. Since WordPress themes are distributed via the official WordPress repository or third-party marketplaces, any site using an outdated version of Elessi is at risk. There is no known compromise of the theme’s supply chain, but the absence of a patch means site administrators must manually apply mitigations or remove the theme.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The vulnerable component remains the same.
• Confidentiality (C): High (H) – Full file read capability.
• Integrity (I): None (N) – No file modification.
• Availability (A): None (N) – No denial of service.

CVSS Score: 7.5 (High) – The vulnerability allows unauthenticated remote file disclosure, which can lead to further compromise.

Deep Dive & Mechanics

The Elessi theme uses PHP’s include() or require() functions to load template parts or configuration files. The filename parameter is not properly sanitized, allowing path traversal sequences (e.g., ../../) to escape the intended directory. An attacker can craft a request like:

GET /wp-content/themes/elessi/template.php?file=../../../../etc/passwd HTTP/1.1

If the theme passes the file parameter directly to include(), the server will read and output the contents of /etc/passwd. This is a classic Local File Inclusion vulnerability, distinct from Remote File Inclusion (RFI) because the attacker cannot include remote URLs unless allow_url_include is enabled (which is rare). However, LFI alone is sufficient to leak sensitive data.

Vulnerable vs. Patched Code

Vulnerable Code (version < 6.4.1):

<?php
// vulnerable.php
$file = $_GET['file'];
include($file . '.php');
?>

Patched Code (version 6.4.1+):

<?php
// patched.php
$allowed_files = array('header', 'footer', 'sidebar');
$file = $_GET['file'];
if (in_array($file, $allowed_files)) {
    include($file . '.php');
} else {
    // error handling
}
?>

The patched version uses a whitelist approach, only allowing predefined filenames. This prevents any arbitrary file inclusion.

Exploitation & Lab Setup

Red Team (Attacker)

Lab Setup:

1. Install WordPress with Elessi theme version 6.4.0.
2. Ensure the vulnerable endpoint exists (e.g., /wp-content/themes/elessi/template.php).

Exploitation Steps:

1. Identify the vulnerable parameter (e.g., file).
2. Send a crafted request to read /etc/passwd:

   GET /wp-content/themes/elessi/template.php?file=../../../../etc/passwd HTTP/1.1
   Host: target.com
   

3. If successful, the server returns the contents of /etc/passwd.

Note: No public exploit code is available, so manual testing is required.

Blue Team (Defender)

Detection:

• Monitor web server logs for path traversal patterns (e.g., ../).
• Look for requests to theme files with unexpected parameters.
• Use the detection rules provided below.

Mitigation:

• Immediately update to version 6.4.1 or later.
• If patching is not possible, disable the vulnerable theme or implement a Web Application Firewall (WAF) rule to block path traversal attempts.

Indicators of Compromise (IOCs)

• File Paths: /etc/passwd, /etc/shadow, /wp-config.php, .env
• HTTP Requests: GET requests containing ../ or ..\\ in parameters.
• Log Entries: Repeated 200 responses to non-existent files with path traversal sequences.
• Network Traffic: Outbound connections from the web server to internal files (unusual for normal operation).

Detection Engineering

YARA Rule

rule CVE_2025_49070_Elessi_LFI {
    meta:
        description = "Detects attempts to exploit CVE-2025-49070 in Elessi theme"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-49070"
    strings:
        $path_traversal = /\.\.\/|\.\.\\/
        $elessi_param = /file\s*=\s*[^&]*\.\.\//
    condition:
        $path_traversal and $elessi_param
}

Sigma Rule

title: CVE-2025-49070 Elessi LFI Detection
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects path traversal attempts targeting Elessi theme
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains: 
            - 'file=../'
            - 'file=..\\'
    condition: selection
falsepositives:
    - Legitimate use of relative paths in other contexts
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-49070 Elessi LFI Attempt"; flow:to_server; content:"GET"; http_method; content:"/wp-content/themes/elessi/"; http_uri; content:"file="; http_uri; pcre:"/file\s*=\s*[^&]*\.\.\//i"; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Update the Elessi theme to version 6.4.1 or later. If unavailable, remove the theme entirely.
2. WAF Rules: Block requests containing ../ or ..\\ in query parameters.
3. PHP Configuration: Disable allow_url_include and set open_basedir to restrict file access.
4. File Permissions: Ensure sensitive files (e.g., wp-config.php) are not readable by the web server user.
5. Monitoring: Enable logging and alerting for path traversal patterns.
6. Backup: Regularly backup WordPress files and database to recover from potential compromise.

Valters IT