Broken Access Control in “Simple Like Page” WordPress Plugin (<= 1.5.3) — What Site Owners Must Know and How to Protect Their Sites

TL;DR

A broken access control vulnerability affecting the “Simple Like Page” WordPress plugin (versions ≤ 1.5.3) has been publicly disclosed (CVE-2025-63022). Unauthenticated requests can reach functionality that should be restricted, enabling an attacker to perform actions normally reserved for privileged users. The reported technical severity is low (CVSS 5.3) and, at disclosure time, there is no official patch. While this is not an immediate remote code execution problem, exposed endpoints undermine site integrity and may be chained with other issues. Prompt mitigation is advised.

Summary of the vulnerability

• Software: Simple Like Page (WordPress plugin)
• Affected versions: ≤ 1.5.3
• Vulnerability type: Broken Access Control (OWASP A01)
• CVE: CVE-2025-63022
• Reported by: Legion Hunter
• Disclosure / publication date: 2025-12-31
• Patch status: No official fix available at time of disclosure

Broken access control here means certain plugin endpoints or actions do not properly verify that the caller has the required authentication, capability, nonce, or permission. The report indicates unauthenticated requests can invoke functionality that should be restricted to privileged users.

Why this matters — risk and real-world impact

• Although classed as low severity (CVSS 5.3), the vulnerability allows unauthenticated modification of plugin-managed data which can affect site integrity and trust.
• Potential impacts include altering like counters, changing plugin options, or triggering functions that write to the database or modify content.
• Attackers can use such endpoints as part of a wider chain to escalate privileges or persist access.
• Because scanning and exploitation are inexpensive to automate, many sites can be targeted quickly; low technical severity does not imply low operational risk.

Exploitability — how easy is this to abuse?

• Authentication required? No — reported as unauthenticated.
• Preconditions: Plugin installed and publicly reachable.
• Complexity: Low — the core problem is missing or insufficient access checks. Turning that into impactful compromise may require additional factors, but probing and basic abuse is straightforward.
• Public PoC: None published in the CVE record; responsible disclosure practices aim to avoid publishing working exploits.

Because the endpoint is accessible without credentials, automated scanners can enumerate and test large numbers of sites. Rapid mitigation of exposed instances is recommended.

Immediate actions for site owners (short checklist)

1. Identify whether your site uses Simple Like Page (plugin slug: simple-facebook-plugin / Simple Like Page) and confirm the installed version.
2. If you run version ≤ 1.5.3:
   • Temporarily deactivate the plugin if it is not essential.
   • If deactivation breaks critical functionality, apply access restrictions to plugin endpoints (see suggestions below).
3. Restrict access to plugin endpoints: block or require authentication for any AJAX or admin paths that should not be publicly reachable.
4. Harden admin access: enforce strong passwords, restrict login attempts, and enable two‑factor authentication for privileged accounts.
5. Scan for suspicious changes and review logs for unauthorized requests.
6. Prepare to update the plugin when a fixed version is released; do not re-enable until patched and validated.

How managed WAF or hosting WAF can help (mitigations while waiting for a patch)

While awaiting an official plugin update, a managed web application firewall (WAF) or hosting WAF can reduce exposure by intercepting and blocking malicious requests at the edge. Typical mitigations include:

• Virtual patching: temporary rules that deny unauthenticated access to sensitive plugin endpoints without changing plugin code.
• Request validation: blocking requests that lack valid nonces, expected referer headers, or authenticated cookies for known write actions.
• Rate limiting and anomaly detection: throttle or block high-volume probing attempts.
• Blocking known malicious scanners and IP lists to limit automated discovery.
• File and integrity monitoring to detect unexpected modifications to plugin files or data.

Use these controls as stop-gap measures; they do not replace the need for a proper code fix in the plugin itself.

What to enable in your WAF (technical guidance)

If you manage your own WAF or can provide rules to your hosting provider, consider the following defensive actions. These are intentionally generic to avoid revealing exploitation details:

1. Block unauthenticated POST/GET requests to plugin admin or AJAX endpoints.
   • Identify plugin request patterns (for example, requests referencing the plugin directory or action parameters passed to admin-ajax.php).
   • Deny requests that attempt state changes without a valid WordPress nonce or a logged-in session cookie.
2. Require WP nonce verification for state-changing POSTs — drop requests missing expected nonce values for endpoints that change state.
3. Rate limit requests targeting the plugin endpoints to reduce scanning effectiveness.
4. Block requests with unusual user agents or known scanner signatures.
5. Where possible, whitelist administrative IPs for sensitive endpoints to reduce the attack surface.
6. Monitor and log all blocked events for follow-up analysis.

Detection — how to tell if you were targeted or exploited

Check server and application logs for the following indicators:

• Unusual requests to plugin file paths or admin-ajax.php where the “action” parameter references the plugin.
• POST requests from anonymous IP addresses invoking plugin actions that normally require authentication.
• Sudden or unexplained changes to like counters or plugin-managed content.
• Unexpected database writes in tables used by the plugin (timestamped entries outside expected patterns).
• Anomalous spikes in 4xx/5xx responses for plugin endpoints.
• New options, transients, or database entries added by the plugin you did not expect.
• Subsequent suspicious behaviour after a request attempt (new user accounts, modified posts).

If you detect suspicious activity, preserve logs, take a site snapshot, and follow incident response steps below.

If you suspect your site has been compromised — incident response

1. Isolate the site: place it behind maintenance or take it offline while investigating.
2. Preserve evidence: save access and error logs, application logs, and snapshots of the database and filesystem.
3. Revoke credentials: reset passwords for WordPress admin users, database users, and hosting control panel accounts.
4. Scan for malware: run a reputable WordPress malware scanner and review flagged files.
5. Review plugin settings and database entries for unauthorised changes.
6. Restore from a known-good backup if integrity cannot be confirmed; prefer backups taken before the suspected compromise.
7. Harden and patch: disable the vulnerable plugin until a secure version is released or until mitigations are in place; update other components (core, themes, plugins).
8. Recheck and monitor: after remediation, monitor logs and validate that any edge rules are effective.
9. Notify stakeholders and follow any applicable disclosure or regulatory requirements if user data may have been affected.

Developer guidance — how the plugin should be fixed

Developers and maintainers should apply standard, proven controls to remediate broken access control:

1. Principle of least privilege: every action must check that the current user has the minimal capability required (for example, current_user_can(‘manage_options’) or a more specific capability).
2. Nonce protection for state-changing actions: require and validate nonces for POST requests that change site state (wp_create_nonce() on the client and wp_verify_nonce() on the server).
3. Permission callbacks for REST routes: when registering REST endpoints with register_rest_route(), include a permission_callback that verifies capability.
4. Sanitise input and escape output: sanitize $_POST/$_GET with sanitize_text_field(), absint(), esc_url_raw(), etc., and escape output with esc_html(), esc_attr() when rendering.
5. Avoid using admin-ajax.php for privileged public actions. If an action must be public, keep it read-only and rate-limited; write actions require authentication and nonces.
6. Unit tests and permission tests: add tests that call endpoints as unauthenticated users and assert they are denied.

Example server-side handler pattern:

<?php
function slp_update_setting() {
    // Check user capability
    if ( ! current_user_can( 'manage_options' ) ) {
        wp_send_json_error( array( 'message' => 'Unauthorized' ), 403 );
    }

    // Verify nonce
    $nonce = isset( $_REQUEST['_wpnonce'] ) ? sanitize_text_field( wp_unslash( $_REQUEST['_wpnonce'] ) ) : '';
    if ( ! wp_verify_nonce( $nonce, 'slp_update' ) ) {
        wp_send_json_error( array( 'message' => 'Invalid nonce' ), 403 );
    }

    // Sanitize and process input
    $value = isset( $_POST['value'] ) ? sanitize_text_field( wp_unslash( $_POST['value'] ) ) : '';
    update_option( 'slp_setting', $value );

    wp_send_json_success( array( 'message' => 'OK' ) );
}
add_action( 'wp_ajax_slp_update_setting', 'slp_update_setting' );
?>

Recommendations for hosting providers and site operators

• Maintain up-to-date backups and test restore procedures.
• Apply least privilege to database and file-system accounts.
• Restrict plugin installations to trusted administrators and perform code review for plugins in high-risk environments.
• Enforce secure file permissions (e.g., limit write access to wp-content where feasible).
• Enable monitoring and alerting on sudden permission changes, new admin users, or unusual outbound connections.

Frequently asked questions

Q: The vulnerability is “low severity” — should I worry?
A: Yes. “Low” refers to technical impact in CVSS terms, but easy-to-automate flaws that are discoverable at scale can result in reputational damage, data tampering, or be leveraged in multi-step attacks. Treat exposed sites as at risk.

Q: Should I delete the plugin?
A: If the plugin is not required, deactivate and delete it. If it is needed for business reasons, restrict access, apply compensating controls, and monitor closely until a fixed version is available.

Q: When will a patch be available?
A: At disclosure time there is no confirmed fixed version. Monitor the plugin’s official distribution channel and the WordPress plugin repository for updates, and apply them as soon as they are released and validated.

Practical example: a safe rule you can enable (conceptual)

The following is a conceptual WAF rule — adapt to your WAF engine and test on staging:

• Drop/deny requests where:
  • Request URI contains the plugin directory (e.g., /wp-content/plugins/simple-facebook-plugin/) AND
  • HTTP method is POST or otherwise state-changing AND
  • No valid WordPress logged-in cookie present OR no expected nonce header present.
• Log all blocked requests and notify administrators for investigation.

Closing notes — pragmatic, layered defence

Broken access control is a common but preventable class of vulnerability. Keep the defence simple and layered:

• Keep software updated.
• Use edge controls (WAF) to reduce exposure while awaiting vendor fixes.
• Limit publicly reachable functionality and enforce least privilege in code.
• Build permission checks, nonces, and sanitisation into the development lifecycle and tests.

References & credits

• CVE-2025-63022 — Broken Access Control in Simple Like Page (public disclosure: 2025-12-31)
• Researcher: Legion Hunter (initial report)