Remediation & cleanup if you find malicious payloads

1. Take the site to maintenance mode if practical.
2. Backup the site and database (snapshot for forensics).
3. Remove malicious content from posts and postmeta; restore safe revisions.
4. Rotate admin passwords, API keys and other secrets.
5. Invalidate sessions and require password resets for admins/editors.
6. Scan files for webshells and unauthorized changes (focus on wp-content/uploads, themes, plugins).
7. Remove unknown scheduled tasks, suspicious users and options.
8. If credentials were exfiltrated, escalate to full incident response and forensic analysis.
9. After cleanup, reinstall WordPress core, themes and plugins from trusted sources.

If you are unsure how to proceed, engage a professional security incident responder.

Developer guidance — secure shortcode patterns and fixes

If you maintain or develop the plugin, fix the shortcode handler and apply robust sanitization and escaping.

Key principles:

• Never echo user input directly.
• Validate inputs strictly (e.g., stock tickers should be alphanumeric and short).
• Sanitize input on save and escape on output.
• Use wp_kses with a strict allowlist if HTML output is required.
• Restrict who can submit HTML (capability checks) and use nonces for requests.

Illustrative safe shortcode handler (example):

function is_valid_stock_symbol( $symbol ) {
    // Accept uppercase letters, numbers, hyphen; max length 10
    return preg_match( '/^[A-Z0-9\-]{1,10}$/', $symbol );
}

function safe_stock_shortcode_handler( $atts ) {
    $atts = shortcode_atts( array(
        'symbol' => '',
        'show'   => 'price',
    ), $atts, 'stock' );

    // sanitize attributes
    $symbol = strtoupper( sanitize_text_field( $atts['symbol'] ) );
    if ( ! is_valid_stock_symbol( $symbol ) ) {
        return '';
    }

    $show = sanitize_text_field( $atts['show'] );
    $allowed_show = array( 'price', 'change', 'name' );
    if ( ! in_array( $show, $allowed_show, true ) ) {
        $show = 'price';
    }

    $symbol_escaped = esc_html( $symbol );
    $show_escaped   = esc_attr( $show );

    $output  = '';
    $output .= '' . $symbol_escaped . '';
    $output .= '';

    return $output;
}
add_shortcode( 'stock', 'safe_stock_shortcode_handler' );

Notes:

• Validate symbols; reject unexpected input.
• Use sanitize_text_field and escaping functions (esc_html, esc_attr).
• Only allow raw inner HTML for users with appropriate capabilities and sanitise with wp_kses using a strict allowlist.
• Do not store untrusted HTML or scripts in postmeta or options.

Example hardening changes at plugin level

• Add capability checks so raw HTML is only accepted by users with unfiltered_html capability.
• Escape on output: esc_html() for text nodes, esc_attr() for attributes.
• Sanitize before storing and escape again on output — defence in depth.
• Use nonces for AJAX and form endpoints and validate capabilities in REST/AJAX handlers.

WAF / virtual patching perspective (general guidance)

When a plugin fix is not yet available, virtual patching via a WAF or hosting-level rules can reduce risk. Goals for rules:

• Block attempts to save shortcodes containing script tags or inline event handlers.
• Block admin/post requests with common XSS signatures in POST bodies.
• Optionally, neutralise or strip script tags from POST payloads before WordPress saves them (use with caution).
• Prevent stored XSS payloads that reference sensitive APIs (e.g., document.cookie, XMLHttpRequest) from being saved.

Operational advice:

• Tune rules to reduce false positives; some legitimate content may contain code samples.
• Prefer challenge (captcha) in sensitive situations where false positives are likely, rather than outright block.
• Log all blocked attempts and investigate the sources of blocked traffic.

Suggested WAF regex examples (illustrative)

Test these on a staging environment before deploying to production.

• Block POST requests where a [stock shortcode contains script tags or suspicious patterns:

  (?i)\[stock[^\]]*(|on\w+\s*=|javascript:|data:text/html)

• 阻止內聯事件處理程序：

  (?i)on(?:click|mouseover|load|error|submit)\s*=

• 阻止 javascript: URI：

  (?i)javascript\s*:

根據您的環境調整規則，以避免破壞合法內容。.

長期加固檢查清單

• 最小權限：僅在必要時授予貢獻者/編輯者角色；考慮具有更嚴格能力的自定義角色。.
• 編輯工作流程：要求審查並限制誰可以預覽或發布包含短代碼的內容。.
• 對不受信任的角色禁用危險的短代碼。.
• 確保 unfiltered_html 不會授予不受信任的角色。.
• 應用嚴格的內容安全政策 (CSP) 以減少內聯腳本的影響（並不能替代適當的清理）。.
• 維護已安裝插件/主題的清單，並移除未使用的項目。.
• 定期備份和測試恢復程序。.
• 基於角色的測試：模擬貢獻者工作流程以識別不安全的渲染路徑。.
• 監控伺服器和 WAF 日誌以查找異常和被阻止的 XSS 嘗試。.

事件響應手冊（簡要）

1. 包含： 停用插件，禁用短代碼，必要時將網站下線。.
2. 分類： 確定注入的帖子/元數據，收集日誌並保留證據。.
3. 清理： 移除有效載荷、未知的管理用戶和已更改的文件。.
4. 恢復： 從乾淨的備份恢復或從可信來源重新安裝組件。.
5. 事後分析： 確定根本原因，修補並更新流程以避免重演。.
6. 通知： 如果用戶數據被暴露，遵循法律和披露義務。.

如何在數據庫中檢測易受攻擊的短代碼（快速 SQL）

搜尋包含短代碼和可能的腳本標籤的帖子：

選擇 ID, post_title

SELECT post_id, meta_key, meta_value
FROM wp_postmeta
WHERE meta_value LIKE '%[stock%'
OR meta_value LIKE '%

wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%[stock%' AND post_content LIKE '%

// Neutralize 'stock' shortcode: return safe placeholder and log the incident
if ( shortcode_exists( 'stock' ) ) {
    remove_shortcode( 'stock' );
    add_shortcode( 'stock', function( $atts ) {
        error_log( 'Blocked stock shortcode rendering in ' . (is_admin() ? 'WP-admin' : 'Front-end') );
        return '';
    } );
}