CVE-2025-31387: InstaWP Connect LFI Vulnerability

CVE-2025-31387 Overview

CVE-2025-31387 is a PHP Local File Inclusion (LFI) vulnerability affecting the InstaWP Connect WordPress plugin. The vulnerability stems from improper control of filename for include/require statements in PHP, allowing attackers to include arbitrary local files on the server. This flaw is classified under CWE-98 (Improper Control of Filename for Include/Require Statement in PHP Program).

Critical Impact

Attackers can exploit this vulnerability to read sensitive files, potentially execute arbitrary PHP code through log file poisoning or other techniques, and compromise the confidentiality, integrity, and availability of affected WordPress installations.

Affected Products

• InstaWP Connect WordPress plugin versions from n/a through 0.1.0.82
• WordPress installations using the vulnerable instawp-connect plugin
• Web servers hosting WordPress sites with InstaWP Connect enabled

Discovery Timeline

• 2025-03-31 - CVE-2025-31387 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-31387

Vulnerability Analysis

This vulnerability allows attackers to manipulate file path parameters to include arbitrary local files on the server through PHP's include or require functions. The attack requires network access with high complexity and user interaction, but can result in complete compromise of confidentiality, integrity, and availability of the affected system.

The vulnerability exists due to insufficient validation and sanitization of user-supplied input that controls file paths used in PHP include or require statements. When exploited, an attacker can force the application to include files from anywhere on the local filesystem that the web server process has read access to.

Root Cause

The root cause of CVE-2025-31387 is improper input validation in the InstaWP Connect plugin's file handling logic. The plugin fails to adequately sanitize or restrict user-controlled input before passing it to PHP include/require functions. This allows attackers to manipulate the file path parameter using directory traversal sequences (such as ../) or absolute paths to include unintended files.

PHP's include and require functions are particularly dangerous when combined with user input, as they will execute any PHP code contained within included files. This creates a pathway from file inclusion to potential code execution.

Attack Vector

The attack vector for this vulnerability is network-based, requiring the attacker to send specially crafted requests to a vulnerable WordPress installation. The exploitation involves manipulating parameters that control file paths in include statements.

A typical attack scenario involves:

1. Identifying a WordPress site running InstaWP Connect version 0.1.0.82 or earlier
2. Crafting malicious requests with directory traversal sequences to include sensitive files
3. Reading configuration files containing database credentials or other sensitive data
4. Potentially achieving code execution through log file poisoning or inclusion of uploaded files

For detailed technical information about this vulnerability, refer to the Patchstack Vulnerability Report.

Detection Methods for CVE-2025-31387

Indicators of Compromise

• Unusual requests containing directory traversal patterns such as ../ or encoded variants (%2e%2e%2f) targeting InstaWP Connect plugin endpoints
• Web server logs showing attempts to access sensitive files like /etc/passwd, wp-config.php, or log files through plugin parameters
• Unexpected file access patterns from the web server process, particularly reads of configuration or system files
• Failed or successful attempts to include PHP files from non-standard locations

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block requests containing directory traversal sequences
• Monitor web server access logs for requests to InstaWP Connect endpoints with suspicious path parameters
• Deploy file integrity monitoring on WordPress configuration files and plugin directories
• Use intrusion detection systems configured with signatures for PHP LFI attack patterns

Monitoring Recommendations

• Enable verbose logging on WordPress and web server to capture full request URLs and parameters
• Set up alerts for any access to sensitive system files from the web server process context
• Monitor for unusual PHP error messages that may indicate failed inclusion attempts
• Regularly audit installed WordPress plugins and their versions against known vulnerability databases

How to Mitigate CVE-2025-31387

Immediate Actions Required

• Update InstaWP Connect plugin to a version newer than 0.1.0.82 if a patched version is available
• Temporarily disable the InstaWP Connect plugin if an update is not immediately available
• Review web server logs for any indicators of attempted or successful exploitation
• Implement WAF rules to block requests containing path traversal patterns targeting the plugin

Patch Information

Organizations should check the WordPress plugin repository for updated versions of InstaWP Connect that address this vulnerability. The Patchstack Vulnerability Report provides additional guidance on remediation.

If a patched version is not yet available, consider the workarounds below to reduce risk until an official fix is released.

Workarounds

• Disable the InstaWP Connect plugin through the WordPress admin dashboard until a patch is available
• Implement server-level restrictions using .htaccess or nginx configuration to block direct access to vulnerable plugin files
• Use a Web Application Firewall to filter requests containing directory traversal sequences
• Restrict PHP's open_basedir configuration to limit file access to the WordPress directory structure

# Apache .htaccess workaround to block suspicious requests to the plugin
<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{REQUEST_URI} instawp-connect [NC]
    RewriteCond %{QUERY_STRING} (\.\.\/|\.\.\\) [NC,OR]
    RewriteCond %{QUERY_STRING} (%2e%2e%2f|%2e%2e\/|\.\.%2f) [NC]
    RewriteRule .* - [F,L]
</IfModule>