CVE-2017-7723 in Easy WP SMTP Plugin
Summary
by MITRE
XSS exists in Easy WP SMTP (before 1.2.5), a WordPress Plugin, via the e-mail subject or body.
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Analysis
by VulDB Data Team • 09/20/2020
The vulnerability CVE-2017-7723 represents a cross-site scripting flaw in the Easy WP SMTP WordPress plugin version 1.2.4 and earlier. This issue arises from insufficient input sanitization within the plugin's email handling functionality, specifically when processing email subject lines and body content. The vulnerability allows attackers to inject malicious scripts that execute in the context of other users' browsers when they view email messages containing the crafted payloads. The flaw demonstrates a classic lack of proper output encoding and input validation that violates fundamental web application security principles.
The technical implementation of this vulnerability stems from the plugin's failure to properly sanitize user-supplied data before rendering it within email templates. When administrators or users view emails processed through the Easy WP SMTP plugin, the malicious scripts contained in the subject or body fields can execute in the browser context of other users. This occurs because the plugin does not adequately escape special characters or validate input before displaying email content, creating an environment where attacker-controlled data can be interpreted as executable code rather than plain text. The vulnerability maps to CWE-79, which specifically addresses cross-site scripting flaws due to improper output encoding.
The operational impact of CVE-2017-7723 extends beyond simple script execution, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, and redirection to malicious sites. An attacker who can inject scripts into email messages could potentially steal administrator credentials, modify website content, or redirect users to phishing sites that appear legitimate within the WordPress interface. This vulnerability particularly affects WordPress environments where administrators frequently access email notifications through the web interface, making it a significant threat vector for compromised WordPress installations. The attack pattern aligns with ATT&CK technique T1190, which covers exploiting vulnerabilities in web applications to gain unauthorized access.
Organizations should immediately upgrade to Easy WP SMTP version 1.2.5 or later, which includes proper input sanitization and output encoding fixes. System administrators should also implement additional security measures such as input validation at multiple layers and regular security audits of installed plugins. The remediation process should include comprehensive testing to ensure that email functionality continues to work properly after applying the patch while maintaining security. Security monitoring should be enhanced to detect unusual email content patterns that might indicate exploitation attempts. This vulnerability underscores the critical importance of keeping WordPress plugins updated and following secure coding practices that prevent XSS attacks through proper data validation and output encoding.