Executive summary

A Local File Inclusion (LFI) vulnerability has been disclosed for the HealthFirst WordPress theme affecting version 1.0.1 and earlier (CVE‑2025‑69408). This is a high‑priority issue (CVSS 8.1): unauthenticated attackers can include and read local files from your web server. In many environments LFI can be chained into a full compromise (credential disclosure, backdoor installation, or remote code execution via log‑poisoning or PHP wrappers). If your site runs HealthFirst ≤ 1.0.1 (or a derivative), act immediately.

This advisory provides a concise technical explanation, safe ways to check if you are affected, immediate mitigation steps suitable for site owners and administrators (with context for operators in Hong Kong and the wider APAC region), suggested WAF/virtual patching rules, and long‑term hardening guidance.

Vulnerability at a glance

• Vulnerability: Local File Inclusion (LFI)
• Affected product: HealthFirst WordPress theme
• Affected versions: ≤ 1.0.1
• CVE: CVE‑2025‑69408
• Attack complexity: Low (unauthenticated)
• Privileges required: None
• Impact: Confidentiality / Integrity / Availability — CVSS 8.1
• Exploitation: Read local files; potential for remote code execution when chained (log‑poisoning, PHP wrappers, file upload abuse)

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

Local File Inclusion occurs when an application includes a local file path that can be controlled (fully or partially) by an attacker. In PHP applications such as WordPress themes, this typically arises from include/require calls built from unsanitised user input.

Why this is dangerous:

• An attacker can read sensitive files (for example, wp-config.php with database credentials).
• LFI allows probing the filesystem for secrets, keys and configuration files.
• LFI can be escalated to remote code execution (RCE) using log‑file poisoning or PHP stream wrappers if the server is permissive.
• WordPress sites commonly host valuable user data and privileged admin interfaces, increasing the risk and impact.

Because the HealthFirst LFI is exploitable without authentication, exposure is immediate for any affected site where the theme is active (and in some setups even when present on disk).

How an attacker can (and often will) abuse an LFI

1. Discover the LFI — An attacker locates a parameter (e.g., ?page= or ?template=) that is passed into include/require and supplies traversal sequences like ../../wp-config.php (URL‑encoded as %2e%2e%2f).
2. Read sensitive files — wp-config.php, .env, keys, and other configuration files can be exposed, yielding credentials.
3. Log poisoning → RCE — If attacker data is written to logs (User‑Agent, headers, etc.), those logs can be included via LFI to execute PHP code, turning LFI into full site takeover.
4. Backdoor and persistence — With credentials or code execution, attackers create admin users, upload webshells, or modify files to maintain access.
5. Pivoting — From a compromised site attackers may move laterally to other tenants on shared hosts, exfiltrate data, or use the site for spam and phishing campaigns.

Even a simple file read often leads to a complete compromise in typical WordPress hosting environments.

Technical analysis — typical root cause patterns in vulnerable themes

While we do not publish the exact vulnerable source here, the insecure patterns that cause LFI are common and worth auditing for:

• include( $_GET[‘page’] );
• include( $template );
• require_once( $_REQUEST[‘file’] );
• include_once( $path . $_GET[‘template’] );
• Any include/require that concatenates unsanitised user input into a file path.

Common developer mistakes:

• Not enforcing a whitelist of allowed templates or filenames.
• Incorrect use of realpath() or path checks that can be bypassed.
• Assuming WordPress sanitisation covers include/require usage (it does not).

If you are auditing HealthFirst, search for include/require usage and trace variables back to their source. Treat any dynamic include that can be influenced by request parameters as high risk until proven otherwise.

Safe ways to check whether your site is affected

Do not run destructive exploit tests on live production sites. Use code inspection or a staging copy.

1. Check the installed theme version
   • WP Admin: Appearance → Themes → HealthFirst — verify the version.
   • Server: inspect wp-content/themes/healthfirst/style.css for the theme header and version.
2. Search the theme for risky include/require patterns (non‑destructive)
   • From SSH or your dev environment, run:

     grep -R "include" wp-content/themes/healthfirst
     grep -R "require" wp-content/themes/healthfirst
     grep -R "php://input" wp-content/themes/healthfirst

   • Inspect matches and determine whether variables originate from $_GET, $_REQUEST, $_POST, or similar.
3. Check for untrusted input usage
   • Trace variables used in include/require calls; if they derive from user input without validation/whitelisting, treat it as vulnerable.
4. Use a non‑invasive scanner or professional audit
   • Run a reputable non‑destructive scanner or engage a security consultant for verification. Avoid executing public exploit code against production systems.

If you are unsure, proceed immediately to mitigation and engage a professional for an audit.

Immediate actions you should take (site owners & administrators)

These steps are prioritised for rapid risk reduction. Operators in Hong Kong and similar regulatory jurisdictions should document actions taken for compliance and post‑incident reporting.

1. If the theme is active — put your site into a protected state
   • Temporarily switch to a default WordPress theme (e.g., Twenty Twenty‑Three) or deactivate HealthFirst until a safe patch is available.
   • If you rely heavily on the theme, restore a recent clean backup into a staging environment for testing.
2. Apply virtual patching (WAF) immediately
   • Deploy WAF rules that block directory traversal sequences, LFI payloads and attempts to request sensitive system files. If you have a managed WAF or host‑level firewall, enable emergency rule sets. Contact your hosting provider if you need assistance.
3. Restrict access to sensitive files
   • Protect wp-config.php from direct web access using web server config or .htaccess.
   • Disable directory listing on the site.
4. Harden file permissions
   • Files: 644 (or 640 where appropriate). Directories: 755 (or 750). wp-config.php: 600 or 440 depending on host.
   • Avoid granting write permissions to the web server for theme/plugin files unless strictly necessary.
5. Disable file editing inside the admin

   // Add to wp-config.php
   define('DISALLOW_FILE_EDIT', true);
   define('DISALLOW_FILE_MODS', true); // only if you understand this disables plugin/theme updates from WP Admin

6. Rotate credentials and keys (if compromise suspected)
   • Change WordPress admin passwords and database/FTP/SFTP credentials. Update wp-config.php accordingly.
   • Regenerate WordPress salts and keys in wp-config.php.
7. Scan for indicators of compromise
   • Check for recently modified files in wp-content, themes, plugins, and uploads.
   • Search for suspicious PHP files, webshells, or obfuscated code.
   • Review user accounts, scheduled tasks, and autoloaded entries in wp_options.
8. Audit logs
   • Inspect access logs for requests containing ../, %2e%2e%2f, php://, etc. If you find probing activity, escalate investigation.
9. Backup your site now
   • Create a full backup (files + database) and store it offline for investigation and rollback.

Recommended virtual patch / WAF rules and detection signatures

Virtual patching using a WAF is the quickest mitigation to reduce immediate exposure while you prepare and test a permanent code patch. Test rules in monitor/report mode first where possible to avoid false positives.

Rule concepts to apply (case‑insensitive):

• Block directory traversal: patterns such as ../ or %2e%2e%2f and multiple traversal sequences.
• Block references to sensitive files: requests containing wp-config.php, /etc/passwd, .env, private key markers (BEGIN RSA PRIVATE KEY).
• Block PHP stream wrappers: php://, data://, expect://, zip://, compress.zlib:// in parameters.
• Block null byte bypasses: %00 or raw null bytes in parameters used for file access.
• Block suspicious include patterns: parameter values ending in .php combined with traversal sequences.
• Throttle & blacklist: rate‑limit repeated scanning attempts and temporarily block IPs exhibiting scanning behaviour.
• Focused parameter rules: if the vulnerable theme uses a known parameter name (e.g., template or view), create a rule that inspects that parameter specifically for traversal or wrapper usage.
• Logging & alerting: ensure blocked attempts generate alerts for investigation.

Example ModSecurity‑style rule (illustrative — adapt to your WAF):

# Disallow directory traversal targeting local files
SecRule ARGS|ARGS_NAMES|REQUEST_URI "@rx (\.\./|%2e%2e%2f|php\://|data\:/)" \
    "phase:2,deny,log,status:403,msg:'LFI/Traversal attempt blocked',id:1000010,severity:2"

Note: rules reduce exposure but do not replace a secure code fix. Coordinate WAF rules with your hosting provider or security team and test thoroughly.

Safe fix examples (developer checklist)

The safest approach is to remove dynamic includes driven by user input or strictly constrain them with a whitelist and path validation.

1. Whitelisting

// Allowed templates:
$allowed_templates = array('home', 'recipes', 'contact');

// Sanitize user input
$page = isset($_GET['page']) ? preg_replace('/[^a-z0-9_-]/i', '', $_GET['page']) : 'home';

if ( in_array( $page, $allowed_templates, true ) ) {
    include get_template_directory() . '/templates/' . $page . '.php';
} else {
    include get_template_directory() . '/templates/404.php';
}

2. Use fixed mappings

$mapping = array(
   'home' => 'templates/home.php',
   'recipes' => 'templates/recipes.php',
   'contact' => 'templates/contact.php',
);

$key = isset($_GET['page']) ? preg_replace('/[^a-z0-9_-]/i', '', $_GET['page']) : 'home';

if ( array_key_exists( $key, $mapping ) ) {
    include get_template_directory() . '/' . $mapping[$key];
} else {
    include get_template_directory() . '/templates/404.php';
}

3. Validate resolved path

$base = realpath( get_template_directory() . '/templates' );
$requested = realpath( $base . '/' . $page . '.php' );

if ( $requested && strpos( $requested, $base ) === 0 ) {
    include $requested;
} else {
    // blocked - invalid path
}

Do NOT accept raw user input into include/require calls. Prefer whitelisting and deterministic mappings.

Incident response & recovery checklist

If you confirm exploitation or strong indicators of compromise, follow these steps in order:

1. Isolate — Take the site offline if persistent backdoors or active compromise are suspected.
2. Backup — Create a full forensic backup (files + DB).
3. Rotate secrets — Change WP admin passwords, API keys, DB credentials, FTP/SFTP/SSH passwords; reissue leaked keys.
4. Investigate — Scan for modified files, unknown admin users, suspicious cron jobs, and unexpected outbound connections.
5. Remove persistence — Delete unauthorized accounts, webshells, and malicious cron entries.
6. Restore from known‑good backup — Restore a clean pre‑compromise backup, patch the vulnerable theme before putting the site back online.
7. Patch & harden — Apply theme updates or safe code patches, harden file permissions, enable WAF mitigation.
8. Monitor — Maintain heightened logging and alerting; watch for re‑infection or repeated attempts.
9. Notify stakeholders — If user data may be exposed, follow applicable breach notification requirements in your jurisdiction.
10. Post‑mortem — Document root cause and corrective actions to prevent recurrence.

If you require containment, forensic analysis, or recovery assistance, engage qualified incident responders promptly.

Long‑term hardening and prevention

• Keep themes, plugins and WordPress core up to date. If a vendor is slow to patch, remove or replace the component rather than waiting.
• Delete unused themes and plugins from disk — do not merely deactivate them.
• Review third‑party code before installation; favour actively maintained and transparent projects.
• Enforce least privilege for database and file ownership.
• Deploy a WAF or equivalent virtual patching to block exploit payloads while code fixes are applied.
• Maintain frequent automated backups with offsite retention and test restores regularly.
• Adopt secure development practices: whitelist inputs, validate outputs, avoid dynamic file includes.
• Enable multi‑factor authentication (MFA) for all admin accounts.
• Maintain a tested incident response plan and contact list for your host and security partners.

Frequently asked questions

Can I safely test for this vulnerability with a web request?

Avoid active exploit attempts on production. Passive code inspection and non‑destructive scans are safe. If an active test is required, do it on a staging copy or behind a temporary WAF in a controlled environment.

My theme is not active but still in wp-content/themes — am I exposed?

Possibly. Some setups load inactive themes (for example, theme previews). If the vulnerable code is reachable via a public URL, treat the site as exposed. Best practice: remove unused themes from the filesystem.

Will virtual patching affect legitimate site functionality?

Well‑designed WAF rules target malicious patterns and aim to minimise false positives. Test rules in reporting/monitor mode before enabling blocking where possible, and review rule hits to fine‑tune.

Final words — act now

Local File Inclusion is one of the vulnerabilities where a small coding oversight often becomes a full compromise. For any site running HealthFirst ≤ 1.0.1, do not delay:

1. Take the theme offline or switch to a safe theme if possible.
2. Enable WAF/virtual patching rules immediately to block exploitation attempts while preparing a code fix.
3. Audit and patch theme files using whitelisting and path validation patterns described above.
4. If you suspect compromise, follow the incident response checklist and engage professional help.

Operators in Hong Kong should also consider any regulatory obligations for breach notification and preserve forensic evidence if an incident is suspected.

If you need help with containment, code auditing, or incident response, consult qualified security professionals or your hosting provider. Prompt action will reduce the chance of data loss, reputational damage, and costly recovery.

— Hong Kong Security Expert — Advisory Team