CVE-2025-49278

Executive Summary

CVE-2025-49278 is a PHP Local File Inclusion (LFI) vulnerability affecting the Blogty WordPress theme developed by Unfoldwp, versions up to and including 1.0.11. The vulnerability stems from improper control of a filename used in a PHP include or require statement, allowing an unauthenticated attacker to include arbitrary local files from the server. This can lead to sensitive information disclosure, such as reading /etc/passwd, WordPress configuration files (wp-config.php), or other system files. The CVSS score of 8.1 (High) reflects the ease of exploitation (no authentication required) and the high impact on confidentiality. No public proof-of-concept (PoC) or exploit code has been identified at this time, but the vulnerability is trivially exploitable via crafted HTTP requests.

Supply Chain & Package Security

This vulnerability resides in a WordPress theme distributed via the official WordPress theme repository and third-party marketplaces. Users who installed Blogty from the WordPress dashboard or manually uploaded the theme are affected. The supply chain risk is elevated because the vendor has not released a patch, leaving all installations vulnerable. Organizations should treat this as a critical supply chain issue and immediately remove or replace 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 is the only affected component.
• Confidentiality (C): High (H) – Full file read capability.
• Integrity (I): None (N) – No file modification possible.
• Availability (A): None (N) – No denial of service.

Threat Level: High. The vulnerability is easy to exploit and can expose sensitive data, including database credentials from wp-config.php.

Deep Dive & Mechanics

The Blogty theme uses a PHP function (likely include() or require()) to load template parts or configuration files. The filename passed to this function is derived from user-supplied input (e.g., via a GET parameter like ?template=...) without proper sanitization or validation. An attacker can inject path traversal sequences (e.g., ../../../../etc/passwd) to include arbitrary files from the server.

Root Cause: The theme does not restrict the file path to a predefined whitelist or sanitize directory traversal characters. This allows an attacker to escape the intended theme directory and read any file the web server process has access to.

Example vulnerable code pattern:

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

An attacker could request ?template=../../../../etc/passwd%00 (null byte injection) or simply ?template=../../../../etc/passwd if the .php extension is appended automatically.

Vulnerable vs. Patched Code

Vulnerable Code (Blogty <= 1.0.11):

// In a theme file (e.g., header.php or functions.php)
$template_part = $_GET['template'];
include( get_template_directory() . '/template-parts/' . $template_part . '.php' );

This code directly uses user input without validation.

Patched Code (Hypothetical fix):

$allowed_templates = array('header', 'footer', 'sidebar');
$template_part = $_GET['template'];
if (in_array($template_part, $allowed_templates)) {
    include( get_template_directory() . '/template-parts/' . $template_part . '.php' );
} else {
    // Default behavior or error
}

A proper fix would whitelist allowed template names and reject any input not in the list.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site running Blogty theme version <= 1.0.11.
• The web server must have read permissions for the target file.

Exploitation Steps:

1. Identify the vulnerable parameter (e.g., template, file, page). Common parameters in WordPress themes include ?template=, ?file=, or ?include=.
2. Craft a request to read /etc/passwd:

   GET /?template=../../../../etc/passwd HTTP/1.1
   Host: target-site.com
   

   If the theme appends .php, use a null byte or path truncation:

   GET /?template=../../../../etc/passwd%00 HTTP/1.1
   

3. Observe the response – the file contents will be included in the page output.

Example curl command:

curl -v "http://target-site.com/?template=../../../../etc/passwd%00"

Blue Team (Detection & Defense)

Detection:

• Monitor web server logs for requests containing ../, %00, or %2e%2e%2f (URL-encoded path traversal).
• Look for requests to the theme directory with unusual parameters (e.g., ?template=...).
• Use the Sigma and Suricata rules provided below.

Defense:

• Immediately disable or remove the Blogty theme if no patch is available.
• Implement a Web Application Firewall (WAF) rule to block path traversal patterns.
• Restrict web server file permissions to prevent reading sensitive files.
• Use a security plugin (e.g., Wordfence) to monitor for LFI attempts.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests containing ../ or %2e%2e%2f in query parameters.
  • Requests to /?template=, /?file=, or similar parameters with path traversal sequences.
  • Unusual inclusion of system files (e.g., /etc/passwd, /etc/shadow) in HTTP responses.

• File System IOCs:

  • Presence of unexpected files in the web root (e.g., /tmp/exploit.php).
  • Modified WordPress configuration files (e.g., wp-config.php with added backdoors).

• Log IOCs:

  • Web server access logs showing 404 or 200 responses for requests with path traversal patterns.
  • PHP error logs indicating failed include() attempts.

Detection Engineering

YARA Rule

rule CVE_2025_49278_LFI_Detection {
    meta:
        description = "Detects LFI attempts targeting Blogty theme CVE-2025-49278"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-49278"
    strings:
        $path_traversal = /(\.\.\/|\.\.\\|%2e%2e%2f|%2e%2e%5c)/
        $vuln_param = /(\?template=|\?file=|\?include=)/
    condition:
        any of ($path_traversal) and any of ($vuln_param)
}

Sigma Rule

title: CVE-2025-49278 Blogty Theme LFI Attempt
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects HTTP requests with path traversal patterns targeting Blogty theme parameters
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-uri-query|contains:
            - '..%2f'
            - '..%5c'
            - '%2e%2e%2f'
            - '%2e%2e%5c'
            - '../'
            - '..\\'
        cs-uri-query|contains:
            - 'template='
            - 'file='
            - 'include='
    condition: selection
falsepositives:
    - Legitimate use of path traversal in other applications (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-49278 Blogty Theme LFI Attempt"; flow:to_server,established; content:"../"; http_uri; nocase; content:"template="; http_uri; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Remove the Blogty theme from all WordPress installations. Replace it with a secure alternative.
2. Scan for compromise – Check for unauthorized file modifications, backdoors, or suspicious user accounts.
3. Rotate credentials – If wp-config.php was exposed, change database passwords, salts, and API keys.

Long-term Mitigation:

• Vendor contact – Attempt to contact Unfoldwp for a patch. If no response, consider forking the theme and applying the fix yourself.
• WAF rules – Deploy a WAF (e.g., ModSecurity) with rules to block path traversal.
• File permissions – Ensure the web server user has minimal read permissions (e.g., chmod 644 for config files, chmod 750 for directories).
• Monitoring – Implement the detection rules above and monitor logs for LFI attempts.

Patch Workaround (if you must keep the theme): Edit the vulnerable file (likely header.php or functions.php) and replace the dynamic include with a whitelist approach as shown in the "Patched Code" section.

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