Post SMTP plugin vulnerability (CVE-2025-24000) with deeper technical insights, attack mitigation steps, real-world impact examples, and multiple layers of solutions.
🛡️ Enhanced Blog Post with Deep Detail, Impact, and Solutions
⚠️ 200K+ WordPress Sites at Risk Due to Critical Post SMTP Plugin Vulnerability (CVE-2025-24000)
A critical vulnerability in the popular Post SMTP plugin for WordPress may allow attackers to hijack administrator accounts, affecting over 200,000 websites globally. This flaw, now tracked as CVE-2025-24000, has a CVSS score of 8.8 and enables privilege escalation by exploiting broken access control in the plugin’s REST API.
🔎 What is Post SMTP and Why It’s Popular
Post SMTP is a highly-rated plugin with 400,000+ active installations, commonly used for:
Replacing WordPress’s default wp_mail() function Sending transactional emails using SMTP or APIs (Gmail, SendGrid, Mailgun, etc.) Email delivery diagnostics Log access for email delivery debugging
Its popularity stems from reliability and support for third-party services. But like any plugin with extended features and logging capabilities, improper access control can lead to severe security issues.
🧨 Understanding the Vulnerability (CVE-2025-24000)
📌 Root Issue:
The plugin’s REST API endpoints verified only whether a user was logged in — not what role they had. That means even Subscribers could access sensitive logs meant only for Administrators.
🔓 Exploit Steps (Privilege Escalation):
An attacker creates a Subscriber account (or exploits an existing one). They access email logs via the vulnerable REST API endpoint. Initiate a password reset for an admin user. The reset email, including the reset link, is visible in the log. The attacker clicks the link and resets the admin password, gaining full control.
This type of attack is called vertical privilege escalation, where a low-permission user becomes an admin — the highest level of control in WordPress.
🔥 Real-World Risks
Backdoor Injection: Attackers can install malicious plugins/themes to maintain access. Phishing Campaigns: Hijacked sites can be used to send spam or phish users. SEO Poisoning: Inserting spammy links to damage your site’s reputation. Ransomware: Locking site content and demanding payment.
📆 Timeline of the Flaw
Date
Event
May 23, 2025
Vulnerability reported to PatchStack
May 26, 2025
Developer provides a fix
June 11, 2025
Version 3.3.0 released with patch
July 2025
Over 200,000+ sites still unpatched
🛠️ Solution: Patch and Harden Your WordPress Site
✅ Step 1: Update the Plugin
Go to Plugins > Installed Plugins Look for Post SMTP If the version is 3.2.0 or lower, update to v3.3.0+ immediately Or download from: Post SMTP Plugin
✅ Step 2: Check Who Has Access
Audit your Users > All Users Remove any suspicious Subscriber accounts Temporarily disable user registration if not needed
✅ Step 3: Enable 2FA for Admins
Use plugins like: Wordfence Login Security Two Factor This ensures even if a password reset is intercepted, the attacker can’t log in
✅ Step 4: Restrict REST API Access
Disable REST API for subscribers with plugins like: Disable REST API Or custom code: add_filter('rest_authentication_errors', function ($result) { if (!is_user_logged_in()) { return new WP_Error('rest_cannot_access', 'REST API restricted.', array('status' => 403)); } return $result; });
✅ Step 5: Scan for Malware or Intrusions
Run a full scan using: Wordfence Security MalCare iThemes Security
📊 Why So Many Sites Are Still at Risk
As of mid-July 2025:
Only 48.5% of users have updated to the patched version Over 200,000 websites remain vulnerable Around 96,800 sites still use v2.x, which have multiple unpatched vulnerabilities
This lag is due to:
Auto-updates disabled Admins unaware of the issue Compatibility concerns with newer versions
🧠 Pro Tips for Future Protection
✅ Enable automatic updates for all trusted plugins. ✅ Subscribe to WordPress security blogs (like jassweb.com 😉). ✅ Use a staging site to test plugin updates before production. ✅ Consider managed WordPress hosting with built-in security scans.
🧾 Final Thoughts
The CVE-2025-24000 vulnerability in Post SMTP is a reminder of the critical role plugin security plays in WordPress site protection. Email delivery is essential — but it must not come at the cost of exposing admin-level access.
If you’re still using an outdated version of Post SMTP, your site is at risk. Update now and take extra steps to harden your WordPress installation against future threats.
