CVE-2025-69071

Executive Summary

CVE-2025-69071 is a critical PHP Local File Inclusion (LFI) vulnerability discovered in the TanTum WordPress theme developed by AncoraThemes. The vulnerability stems from improper control of a filename used in a PHP include/require statement, allowing an unauthenticated attacker to include arbitrary local files from the server. This can lead to sensitive information disclosure, such as reading configuration files (e.g., wp-config.php), source code, or other system files. The CVSS score of 8.1 reflects the high impact on confidentiality with low attack complexity and no required privileges. As of this report, no official patch has been released, and no public proof-of-concept (PoC) or exploit code is available.

Supply Chain & Package Security

This vulnerability affects a WordPress theme, which is part of the broader WordPress ecosystem. Users who have installed the TanTum theme (version 1.1.13 or earlier) are at risk. Since WordPress themes are distributed through official and third-party marketplaces, the supply chain risk is moderate. Administrators should verify the integrity of their theme files and consider disabling or replacing the theme until a patch is available.

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 (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 and the impacted component are the same.
• Confidentiality (C): High (H) – Complete information disclosure is possible.
• Integrity (I): None (N) – No data modification.
• Availability (A): None (N) – No denial of service.

Threat Level: High. The vulnerability is easily exploitable and can lead to the exposure of sensitive data, including database credentials and API keys.

Deep Dive & Mechanics

The vulnerability exists in the TanTum WordPress theme due to improper sanitization of user-supplied input used in a PHP include() or require() statement. Specifically, the theme likely uses a parameter (e.g., page, template, or file) to load dynamic content. Without proper validation, an attacker can manipulate this parameter to include arbitrary files from the server's filesystem.

Example vulnerable code pattern:

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

An attacker could exploit this by sending a request like:

http://target.com/?file=../../../../etc/passwd%00

The null byte (%00) may be used to terminate the string, bypassing the .php extension append. Alternatively, path traversal sequences (../) allow reading files outside the intended directory.

Impact:

• Reading wp-config.php to obtain database credentials.
• Reading /etc/passwd for user enumeration.
• Reading other PHP source code to find additional vulnerabilities.

Vulnerable vs. Patched Code

Since no official patch is available, the following is a hypothetical comparison based on common fixes.

Vulnerable Code (TanTum theme, version <= 1.1.13):

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

Patched Code (Recommended fix):

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

The patched version uses a whitelist of allowed template names, preventing any arbitrary file inclusion.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress installation with TanTum theme version <= 1.1.13.
• Knowledge of the vulnerable parameter (e.g., template, file, page).

Exploitation Steps:

1. Identify the vulnerable parameter by analyzing the theme's source code or through fuzzing.
2. Craft a request to include a sensitive file:

   GET /?template=../../../../wp-config.php%00 HTTP/1.1
   Host: target.com
   

3. If the null byte injection works, the response will contain the contents of wp-config.php.
4. Alternatively, use path traversal without null byte if the extension is not appended:

   GET /?template=../../../../etc/passwd HTTP/1.1
   

Lab Setup:

• Use a local WordPress installation with the TanTum theme.
• Set up a web server (Apache/Nginx) with PHP.
• Monitor logs to observe the attack.

Blue Team (Detection & Defense)

Detection:

• Monitor web server logs for suspicious patterns like ../, %00, or requests to non-existent template files.
• Use WAF rules to block path traversal sequences.
• Implement file integrity monitoring (FIM) to detect unauthorized changes to theme files.

Defense:

• Disable or remove the TanTum theme until a patch is available.
• Apply a virtual patch via WAF to block requests containing ../ or %00 in parameters.
• Restrict file permissions to prevent reading sensitive files.

Indicators of Compromise (IOCs)

• URL Patterns:
  • ?template=../../../../etc/passwd
  • ?file=../../../../wp-config.php%00
  • ?page=../../../../etc/shadow
• Log Entries:
  • HTTP 200 responses to requests with path traversal sequences.
  • Requests to non-existent template files (e.g., ../../../../etc/passwd.php).
• File System:
  • Unauthorized access to /etc/passwd, /etc/shadow, wp-config.php, or other sensitive files.

Detection Engineering

YARA Rule

rule CVE_2025_69071_LFI_Detection {
    meta:
        description = "Detects LFI attempts targeting TanTum theme"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-69071"
    strings:
        $path_traversal = /(\.\.\/){2,}(etc\/passwd|wp-config\.php|proc\/self\/environ)/
        $null_byte = /%00/
        $suspicious_param = /(template|file|page)=.*\.\.\//
    condition:
        any of them
}

Sigma Rule

title: CVE-2025-69071 TanTum Theme LFI Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects LFI attempts against TanTum WordPress theme
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains:
            - '..%2f'
            - '..\\'
            - '%00'
            - '/etc/passwd'
            - '/wp-config.php'
    condition: selection
falsepositives:
    - Legitimate use of path traversal in other contexts (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-69071 TanTum Theme LFI Attempt"; flow:to_server,established; content:"GET"; http_method; content:".."; http_uri; nocase; content:"/etc/passwd"; http_uri; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the TanTum theme and switch to a default WordPress theme (e.g., Twenty Twenty-Four) until a patch is released.
2. Apply a virtual patch using a Web Application Firewall (WAF) to block requests containing path traversal sequences (../, ..\\, %00) in query parameters.
3. Monitor logs for any signs of exploitation.

Long-term Fix:

• The vendor (AncoraThemes) must release a patched version that implements proper input validation and whitelisting of allowed template names.
• Users should update to the latest version once available.

Workaround:

• If the theme cannot be disabled, manually edit the vulnerable PHP file to add input validation (see "Vulnerable vs. Patched Code" section).

Valters IT
Securing Digital Frontiers