Recommended WAF signatures & patterns (conceptual)

Below are conceptual rules for WAFs. Test and tune them in staging — avoid blindly applying complex blocking rules in production without monitoring for false positives.

1. Block SQL metacharacter combinations

   Block requests where resource contains a quote followed by SQL control keywords (e.g., ' OR, ' UNION) or inline comment tokens combined with SQL keywords.

2. Block time-based SQLi patterns

   Throttle or block requests where resource contains SLEEP(, BENCHMARK( or similar functions.

3. Rate-limit and throttle

   If a single IP queries the plugin endpoints more than a threshold within a short time window, challenge (CAPTCHA) or block.

4. Block stacked queries

   Block resource values that include semicolons followed by SQL keywords indicating multiple statements.

5. Monitor encoded payloads

   Capture and inspect decoded parameter values: attackers often double-URL-encode quotes or use hex encoding.

Example conceptual regex patterns (engine-specific syntax will vary):

(?i)(?:%27|')\s*(?:or|and)\s+[^=]*=|(?i)(?:union|select)\s+.*\bfrom\b
(?i)(?:sleep|benchmark)\s*\(

Developer guidance: how this should have been prevented and how to fix correctly

Root cause

The plugin likely constructed SQL using raw user input (resource) without parameterization. Concatenating user input into SQL yields injection risks.

Correct fixes (do not rely on sanitization alone)

1. Use parameterized queries and prepared statements

   WordPress provides $wpdb->prepare() for parameterized queries; use it consistently.

   prepare( "SELECT * FROM {$wpdb->prefix}vibes_table WHERE resource_key = %s", $resource );
   $rows = $wpdb->get_results( $sql );
   ?>
   

   Use %d for integers, %s for strings, and $wpdb->esc_like() for LIKE patterns.

2. Validate and whitelist input

   If resource should match a specific token or format, enforce that with strict validation.

3. Principle of least privilege

   Avoid code that allows arbitrary SQL execution based on user input. Build specific queries and avoid dynamic table/column names derived from raw input.

4. Error handling

   Do not echo raw DB errors to the web. Log errors to secure logs so attackers cannot fingerprint SQL structure.

5. Security testing

   Add SQL injection unit/integration tests and run static/dynamic analysis in CI to detect obvious issues before deployment.

Incident response: If you suspect compromise

1. Contain

   Put the site into maintenance mode or block public access temporarily. Change passwords and keys (WordPress admin, DB user, FTP/SFTP, hosting panel, API keys).

2. Preserve evidence

   Preserve webserver logs, database dumps (read-only copy), and file system snapshots before any cleaning.

3. Assess

   Use malware scanners, manual inspection and trusted tools to find backdoors, modified files, and unauthorized admin users. Check wp_users, wp_usermeta, wp_options, wp_posts.

4. Clean

   Remove malicious files, delete unauthorized users, clean injected content. If the attacker had write access to files and DB, restore from known-clean backup and reapply updates and hardening.

5. Recover

   Apply the vendor patch (update Vibes to 2.2.1+), rotate all credentials, and perform a full post-recovery scan.

6. Report & learn

   Notify affected users if sensitive data was exfiltrated and review patching and detection processes to reduce time-to-patch in future.

Example forensic checklist

• Confirm plugin version: check the plugin header or wp_options active_plugins listing.
• Export the database and run diffs against backups to find changed rows in wp_users, wp_options.
• Search for recently modified files in wp-content:

  find wp-content -type f -mtime -14 -print

• Search for suspicious inline script tags in content:

  SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%

• Check scheduled events:

  SELECT option_name, option_value FROM wp_options WHERE option_name = 'cron';

• Confirm no unknown admin users:

  SELECT user_login,user_email FROM wp_users WHERE ID IN (
    SELECT user_id FROM wp_usermeta WHERE meta_key='wp_capabilities' AND meta_value LIKE '%administrator%'
  );