CVE-2019-25150 in Email Templates Plugin
Summary
by MITRE • 06/07/2023
The Email Templates plugin for WordPress is vulnerable to HTML Injection in versions up to, and including, 1.3. This makes it possible for attackers to present phishing forms or conduct cross-site request forgery attacks against site administrators.
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Analysis
by VulDB Data Team • 04/09/2026
The Email Templates plugin for WordPress presents a significant security vulnerability classified as HTML Injection in versions up to and including 1.3. This flaw exists within the plugin's handling of user input and template processing mechanisms, creating an avenue for malicious actors to inject arbitrary HTML content into email templates. The vulnerability stems from insufficient input sanitization and output escaping within the plugin's template rendering system, allowing attackers to manipulate the email content generation process. The issue manifests when administrators or users interact with the plugin's interface where template variables are processed without proper validation, enabling the injection of malicious HTML code that gets rendered in the final email output.
The technical exploitation of this vulnerability follows established patterns documented in CWE-79 - Cross-Site Scripting and CWE-116 - Improper Encoding or Escaping of Output. Attackers can leverage this weakness to inject malicious scripts or HTML elements into email templates, potentially creating phishing forms that mimic legitimate administrative interfaces. The vulnerability enables attackers to craft deceptive email content that can trick administrators into revealing sensitive credentials or performing unauthorized actions. This HTML injection capability directly aligns with ATT&CK technique T1566.001 - Phishing: Spearphishing Attachment, where attackers can craft malicious email templates that appear legitimate to end users and administrators. The attack surface expands significantly when considering that WordPress administrators often have elevated privileges, making successful exploitation particularly dangerous.
The operational impact of this vulnerability extends beyond simple content manipulation, as it creates persistent attack vectors that can compromise entire WordPress installations. Administrators who process email templates containing malicious HTML injections may unknowingly execute phishing attacks against their own users or gain unauthorized access to administrative interfaces. The vulnerability's persistence means that once injected, malicious HTML content remains active in email templates until manually removed, providing attackers with extended periods of operational capability. This weakness particularly affects organizations relying on WordPress for business-critical communications, where email templates are frequently used for customer notifications, administrative alerts, and user registration processes. The vulnerability's exploitation can result in credential theft, unauthorized administrative access, and potential data breaches, with the attack vector being particularly insidious due to its integration with legitimate email communication channels.
Mitigation strategies for this vulnerability should prioritize immediate plugin updates to versions that address the HTML injection flaw, as well as implementing comprehensive input validation and output escaping mechanisms. Organizations should conduct thorough security assessments of all installed WordPress plugins to identify similar vulnerabilities and establish regular update schedules for third-party components. The implementation of Content Security Policy headers can provide additional protection against malicious HTML injection attempts, while monitoring email templates for unauthorized modifications should be part of routine security operations. Security teams should also consider implementing web application firewalls that can detect and block suspicious HTML injection patterns in email template processing. Regular security training for administrators on recognizing phishing attempts and understanding the risks associated with email template manipulation remains crucial. Organizations should also establish secure coding practices for WordPress plugin development that follow OWASP Top 10 recommendations and incorporate proper input sanitization techniques to prevent similar vulnerabilities from emerging in future implementations.