Urgent: FundEngine (≤ 1.7.4) Local File Inclusion (LFI) — What WordPress Site Owners Must Do Now

Release summary
A critical Local File Inclusion (LFI) vulnerability affecting the FundEngine WordPress plugin (versions ≤ 1.7.4) has been publicly disclosed and assigned CVE-2025-48302. The issue allows a low-privileged user (Subscriber role) to cause the plugin to include arbitrary local files from the web server and render their contents. If exploited, LFI can lead to exposure of sensitive files (including wp-config.php), credential leakage, and potentially full database or site takeover depending on server configuration.

As a Hong Kong-based security practitioner, I have prepared this advisory to help site owners, developers and administrators understand the risk, recognise exploitation attempts, and perform immediate and longer-term remediation. The guidance below is practical and vendor-agnostic.

Table of contents

• What is LFI and why it matters
• CVE details (affected versions, severity)
• How FundEngine’s LFI can be exploited (technical breakdown)
• Example exploit request(s)
• Immediate actions (quick checklist)
• Recommended WAF rules and virtual patch examples
• Secure coding fixes plugin authors should apply
• Detection: what to look for in logs and filesystem
• Incident response: if you suspect compromise
• Long-term hardening and best practices
• What to communicate to stakeholders and users
• Final notes and recommended timeline

What is Local File Inclusion (LFI) and why it matters

Local File Inclusion (LFI) is a vulnerability class where an application accepts user input and uses it to build a file path for an include/require operation (or equivalent) without proper validation. Rather than limiting access to safe files inside a controlled directory, the application can be tricked into reading arbitrary files on the server. An LFI can reveal configuration files (for example wp-config.php), source code, logs, or be chained into remote code execution in misconfigured environments.

Why this is particularly dangerous for WordPress sites:

• WordPress stores DB credentials and salts in wp-config.php. Exposing this file can allow database access or privilege escalation.
• Shared hosting environments commonly host multiple sites on the same server; LFI can reveal details helpful for lateral movement.
• Once publicly disclosed, exploit attempts are rapidly automated and widespread.

Because this FundEngine LFI can be triggered by a Subscriber-level account, the risk is elevated for multi-user sites (membership, donation, community sites) where low-privilege accounts are easy to register.

CVE and affected versions

• Affected software: FundEngine WordPress plugin
• Vulnerable versions: ≤ 1.7.4
• Fixed in: 1.7.5
• CVE: CVE-2025-48302
• Reported privilege: Subscriber (low privilege)
• Severity: CVSS 7.5 (High)

If your site uses FundEngine and the plugin is version 1.7.4 or older, treat this as critical and take immediate action.

How the FundEngine LFI can be exploited (technical breakdown)

At a high level, the vulnerable plugin includes a PHP file based on a user-supplied parameter without correctly restricting the allowed path. Typical characteristics:

• The plugin receives a request parameter (for example page, load, file, or fundpage) and appends it to an include/require statement.
• User-controlled input is not normalised, sanitised, nor restricted to an allowlist.
• An attacker supplies directory traversal sequences (../) or encoded equivalents to escape the intended plugin folder and reference arbitrary local files.
• The server includes the file and echoes its output — text-based sensitive files (config files, logs) can be revealed. In misconfigured setups or with wrappers, this can lead to remote code execution.

Common weaknesses seen in LFI:

• Using include($_GET['page']) or similar patterns without normalisation or realpath checks.
• Failing to block null byte injection, varied encodings (%2e%2e%2f) or PHP wrappers (php://filter).
• Not limiting includes to a safe directory or using an allowlist of acceptable identifiers.

Example exploit request(s)

Illustrative examples for defensive and detection purposes only:

GET /?fundpage=../../../../wp-config.php HTTP/1.1
Host: victim.example
User-Agent: curl/7.88.1
Accept: */*

GET /?fundpage=%2e%2e%2f%2e%2e%2f%2e%2e%2fwp-config.php HTTP/1.1
Host: victim.example

GET /?fundpage=php://filter/read=convert.base64-encode/resource=../../../../wp-config.php HTTP/1.1
Host: victim.example

If the plugin does not sanitise input and directly includes the path, these payloads may cause the site to display wp-config.php contents (or a base64-encoded representation), or other sensitive files such as .env, error logs, or custom configuration files.

Immediate actions — quick checklist (for site owners)

If you host WordPress sites with FundEngine installed, follow these steps right now:

1. Upgrade the plugin. Update FundEngine to version 1.7.5 or later immediately. This is the definitive fix.
2. If you cannot update immediately:
   • Temporarily deactivate the FundEngine plugin.
   • Or deploy a virtual patch (WAF rule) that blocks the vulnerable endpoint or suspicious include-like parameters.
3. Inspect logs for exploitation:
   • Search web server access logs for patterns like .., %2e%2e, php://filter, or requests hitting the plugin endpoints from unknown IPs.
4. Scan for compromise:
   • Run a full malware scan and integrity check of WordPress core, theme and plugin files.
   • Look for new admin users, modified files, and suspicious PHP files.
5. If you find evidence of exposure of wp-config.php or other secrets:
   • Rotate database credentials immediately and update wp-config.php with new credentials.
   • Rotate any API keys, SMTP credentials or other secrets that may have been exposed.
6. Backup current state: Make a forensic backup (files + DB) and isolate it for later analysis.
7. Harden server PHP settings:
   • Disable allow_url_include in php.ini.
   • Restrict open_basedir to WordPress directories if feasible.

Recommended WAF rules and virtual patch examples

Below are sample WAF (Web Application Firewall) rules you can use as a temporary virtual patch until you upgrade to 1.7.5. Tailor rules to your environment and test in staging before production.

1) Block suspicious path-traversal in parameters (ModSecurity example):

SecRule ARGS_NAMES|ARGS "@rx (?:\bfile\b|\bpage\b|\bpath\b|\bview\b|\bfundpage\b)" "phase:2,deny,log,status:403,id:100001,msg:'Block possible LFI attempts - traversal in include param',t:none,t:lowercase,chain"
  SecRule ARGS "@rx (\.\./|\%2e\%2e|\.\.\\x2f|php://|/etc/passwd|wp-config\.php)" "t:none,log"

2) Block attempts using php://filter to read source:

SecRule ARGS|REQUEST_URI "@contains php://filter" "phase:2,deny,log,status:403,id:100002,msg:'Block php://filter attempts'"

3) Prevent base64-encoded reveals:

SecRule REQUEST_URI|ARGS "@rx (base64_encode|convert.base64-encode)" "phase:2,deny,log,status:403,id:100003,msg:'Block base64 encode file read attempts'"

4) Block traversal patterns in encoded forms:

SecRule ARGS "@rx (%2e%2e%2f|%c0%ae%c0%ae|%252e%252e%252f)" "phase:2,deny,log,status:403,id:100004,msg:'Block URL-encoded traversal sequences'"

5) Deny requests to plugin include endpoints from untrusted users:

• If the vulnerable parameter is known (for example fundpage or file), restrict access to logged-in administrators only via cookie verification or block anonymous & subscriber requests to that endpoint.

6) Block attempts to include sensitive files:

SecRule ARGS|REQUEST_URI "@rx (wp-config\.php|\.env|/etc/passwd|/proc/self/environ|config\.inc\.php)" "phase:2,deny,log,status:403,id:100005,msg:'Block access to sensitive files'"

7) Rate-limit suspicious endpoints:

• Implement rate limits on the plugin endpoints to slow automated exploitation attempts and reduce impact while you patch.

Important: adjust rules to the exact parameter name and plugin endpoint used by FundEngine. Generic rules can generate false positives; implement whitelisting for legitimate traffic and monitor logs after changes.

Secure coding fixes plugin developers should apply

If you are a plugin developer or responsible for custom code, the correct fix is to remove any direct inclusion of user-controlled paths and adopt secure practices:

1. Use an allowlist: Map short identifiers to absolute file paths rather than accepting filenames directly.

   $allowed_views = [
     'summary' => plugin_dir_path(__FILE__) . 'views/summary.php',
     'donation' => plugin_dir_path(__FILE__) . 'views/donation.php',
   ];
   
   $requested = isset($_GET['view']) ? sanitize_key($_GET['view']) : 'summary';
   
   if ( isset($allowed_views[$requested]) && file_exists($allowed_views[$requested]) ) {
       include $allowed_views[$requested];
   } else {
       include $allowed_views['summary'];
   }

2. Map identifiers server-side: If you accept file identifiers, resolve them to known safe files; do not concatenate raw input to paths.
3. Canonicalise and verify realpaths:

   $base = realpath(plugin_dir_path(__FILE__));
   $userfile = realpath($base . DIRECTORY_SEPARATOR . $candidate);
   
   if ($userfile === false || strpos($userfile, $base) !== 0) {
       wp_die('Invalid request', 403);
   }
   include $userfile;

4. Reject wrappers and filters: Block php://, data:, zip://, phar:// and similar wrappers in input. Strip null bytes and normalise encodings.
5. Validate user capabilities: Require capability checks (for example current_user_can('manage_options')) or nonce verification for endpoints that include files.
6. Leverage WordPress APIs: Use sanitize_key(), wp_verify_nonce(), current_user_can(), and WP filesystem APIs.
7. Logging and auditing: Log suspicious include attempts (without exposing secrets) for later investigation.

Detection: what to look for in logs and filesystem

Search web server access/error logs and WordPress logs for:

Request patterns

• Requests containing ..%2f, ..%2e, %2e%2e%2f, php://filter, convert.base64-encode, wp-config.php, .env, /etc/passwd.
• Unexpected GET/POST parameters named file, page, view, template, fundpage, load.
• Requests with long encoded payloads or repeated traversal attempts.

Server behaviours

• 200 OK responses to suspicious requests that should return 403.
• Responses returning PHP source or configuration data.
• Repeated requests from a single IP or distributed scanning from many IPs.

Filesystem indicators

• New PHP files in wp-content/uploads or plugin directories.
• Modified core or plugin files (timestamp anomalies).
• Unexpected files with suspicious names (for example phpinfo.php, shell.php).

WordPress indicators

• New admin users you did not create.
• Unknown scheduled tasks (cron events).
• Excessive outbound emails or spikes in traffic to unusual endpoints.

If you detect any of the above, assume possible exposure and follow the incident response guidance below.

Incident response: if you suspect compromise

If you find signs that the vulnerability has been exploited:

1. Isolate
   • Temporarily take the site offline (maintenance mode) or block traffic to the affected endpoint.
   • Remove public access while you investigate.
2. Forensic capture
   • Create a full backup of files and database for investigation (store off-site or offline).
   • Preserve logs from web server, PHP, and any WAF or proxy.
3. Identify scope
   • Determine which files were accessed via LFI and whether any credentials were revealed.
   • Look for post-exploitation indicators: webshells, scheduled tasks, new admin accounts, outbound connections.
4. Credentials rotation
   • If wp-config.php or other secrets were exposed, rotate DB credentials immediately and update wp-config.php.
   • Rotate API keys or tokens that may have been stored on the site.
5. Clean and restore
   • Remove malicious files and revert modified core/plugin/theme files to known-good versions.
   • If extensive or unclear, restore from a pre-compromise backup that has been validated as clean.
6. Rebuild (if necessary)
   • In severe cases, rebuild the server from a clean image and restore content from a verified clean backup.
7. Post-incident monitoring
   • Increase logging and monitoring for several weeks to detect residual access.
   • Consider hiring experienced incident response professionals if you lack in-house capability.
8. Disclosure and transparency
   • Notify affected users if their data or accounts may have been exposed and follow regulatory obligations.

Long-term hardening and best practices

Beyond patching this specific vulnerability, implement these controls to reduce future risk:

1. Keep WordPress core, plugins and themes up to date — prioritise security updates.
2. Reduce the number of active plugins; uninstall unused plugins.
3. Enforce least privilege:
   • Limit registrations or require moderation for new accounts.
   • Only grant users the roles and capabilities they need.
4. Harden PHP and server configuration:
   • Disable allow_url_include.
   • Use open_basedir restrictions where feasible.
   • Keep PHP and OS packages patched.
5. Prevent file editing: set define('DISALLOW_FILE_EDIT', true) in wp-config.php.
6. Use capability checks and nonces for sensitive plugin endpoints.
7. Maintain regular off-site backups with retention policies.
8. Implement file integrity monitoring (checksums) to detect unexpected changes.
9. Deploy and maintain WAF rules as part of a defence-in-depth approach; review blocked traffic to reduce false positives.
10. Conduct periodic security audits and code reviews for custom plugins and themes.
11. Configure alerting for suspicious requests, high error rates, or unexpected administrative events.
12. Educate administrators on safe plugin installation, timely updates, and recognising phishing or social engineering.

Example nginx + ModSecurity configuration snippet (defensive)

Lightweight nginx configuration to deny requests with suspicious traversal or php:// patterns in query strings. Tune this for your environment.

server {
    ...
    location / {
        if ($query_string ~* "(?:\.\./|%2e%2e%2f|php://|convert.base64-encode|wp-config\.php)") {
            return 403;
        }
        try_files $uri $uri/ /index.php?$args;
    }
}

Note: this is a temporary mitigation. The plugin update is the definitive remediation.

What to communicate to stakeholders and users

• Be transparent if personal data may have been exposed. Provide a factual summary of what happened and the actions taken.
• Encourage users to change passwords if there is any chance of credential exposure.
• If payment or donation information may have been affected, notify your payment processor and follow breach notification requirements.
• Provide an expected timeline for resolution and keep communications factual and non-alarming.

Final notes and recommended timeline

1. Immediate (next 1–2 hours)
   • Update FundEngine to 1.7.5. If you cannot, deactivate the plugin or apply a WAF rule that blocks risky parameters.
   • Search logs for php://, wp-config.php, ..%2f and similar payloads.
2. Short-term (within 24–72 hours)
   • Rotate DB and API credentials if you found evidence of exposure.
   • Conduct a malware and integrity scan across the site.
   • Deploy additional hardening (DISALLOW_FILE_EDIT, disable allow_url_include, open_basedir).
3. Medium-term (1–4 weeks)
   • Audit other plugins for insecure file inclusion patterns.
   • Implement role and registration controls for subscribers.
   • Consider a formal security audit if you operate multiple sites or manage high-value assets.

LFI vulnerabilities attract rapid automated exploitation. Updating the plugin is the fastest and most reliable way to protect your site. When immediate updating is not possible, deploy virtual patches, harden the environment, and monitor closely.

If you require hands-on incident response or assistance configuring mitigations, engage qualified security professionals or an experienced incident response provider.

Stay vigilant — patch promptly, monitor continuously, and reduce the attack surface.