YaySMTP – WP Mail SMTP with Email Logs, Tracking & Reports に脆弱性 — CVE-2026-92553
いま何をすべきか
YaySMTP – WP Mail SMTP with Email Logs, Tracking & Reports を 2.7.8 以降に更新してください。
影響を受けるバージョン
- 2.7.7 以下のすべて
対象: プラグイン「YaySMTP – WP Mail SMTP with Email Logs, Tracking & Reports」(yaysmtp)
何が起きるのか
The YaySMTP – WP Mail SMTP with Email Logs, Tracking & Reports plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.7.7 via the putFile function. This is due to insufficient file type validation in the putFile function, as sanitize_file_name() does not strip executable extensions and no allow-list, MIME check, or safe-extension rename is applied. This makes it possible for authenticated attackers, with subscriber-level access and above, to upload files that may be executable, which makes remote code execution possible. The only server-side guard is a .htaccess file containing 'Require all denied' written by writeGuards(), which is silently ignored by nginx and by Apache configured with AllowOverride None, meaning RCE is fully achievable on those server configurations.
ここから先の選択肢
1. 自分たちで対応する
更新の手順、バックアップの取り方、壊れたときの戻し方をまとめています。
2. いまの制作会社・保守業者に頼む
YaySMTP – WP Mail SMTP with Email Logs, Tracking & Reports を使っているかどうかを含めて確認を依頼してください。 無料診断を実行すると、そのまま渡せる依頼文を作れます。
3. 相談先がない・自分では難しい
連絡が取れる相手がいない、管理画面に入れない、侵入された疑いがある。 そうした場合はご相談ください。
出典
- https://plugins.trac.wordpress.org/browser/yaysmtp/tags/2.7.7/includes/Helper/EmailLogAttachments.php#L106
- https://plugins.trac.wordpress.org/browser/yaysmtp/tags/2.7.7/includes/Helper/EmailLogAttachments.php#L178
- https://plugins.trac.wordpress.org/browser/yaysmtp/tags/2.7.7/includes/Helper/EmailLogAttachments.php#L542
- https://plugins.trac.wordpress.org/browser/yaysmtp/tags/2.7.7/includes/Helper/EmailLogAttachments.php#L549
- https://plugins.trac.wordpress.org/browser/yaysmtp/tags/2.7.7/includes/Helper/Utils.php#L814
- https://plugins.trac.wordpress.org/browser/yaysmtp/tags/2.7.7/includes/PluginCore.php#L37