CVE-2025-0957 identifies a stored cross-site scripting (XSS) vulnerability in the SMTP for Amazon SES – YaySMTP plugin for WordPress, affecting all versions up to and including 1.7.1. The root cause is insufficient sanitization of user input and inadequate output escaping during web page generation, which allows attackers to inject arbitrary JavaScript code into pages rendered by the plugin. This vulnerability is exploitable remotely without authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The scope is changed (S:C), meaning the vulnerability affects components beyond the initially vulnerable module, potentially impacting the entire WordPress site. Successful exploitation can lead to confidentiality and integrity breaches, such as stealing cookies, session tokens, or performing actions on behalf of users. Although no public exploits have been reported yet, the vulnerability's characteristics make it a prime target for attackers aiming to compromise websites using this plugin. The YaySMTP plugin is used to facilitate email sending via Amazon SES, and its integration into WordPress sites means a broad attack surface. The vulnerability was reserved in late January 2025 and published in February 2025 by Wordfence, a reputable security vendor. No official patches or updates are currently linked, so mitigation relies on defensive controls and monitoring until a fix is released.

The impact of CVE-2025-0957 is significant for organizations using the YaySMTP plugin on WordPress sites. Exploitation can lead to unauthorized script execution in the context of affected websites, enabling attackers to steal sensitive user information such as authentication cookies, personal data, or perform actions on behalf of legitimate users. This compromises confidentiality and integrity without affecting availability directly. The vulnerability's ability to be exploited remotely without authentication or user interaction increases the risk of widespread attacks. Organizations may face reputational damage, data breaches, and regulatory consequences if user data is exposed. Additionally, attackers could leverage the XSS to deploy further attacks like phishing, malware distribution, or privilege escalation within the compromised site. Given WordPress's extensive global usage, the vulnerability could affect a large number of websites, especially those relying on this plugin for email functionality. The absence of known exploits in the wild currently provides a window for proactive defense, but the risk of future exploitation remains high.

To mitigate CVE-2025-0957 effectively, organizations should: 1) Immediately audit their WordPress installations to identify the presence and version of the SMTP for Amazon SES – YaySMTP plugin. 2) Disable or remove the plugin if it is not essential until a patched version is released. 3) Implement strict input validation and output encoding on all user-supplied data within the plugin's context, if custom modifications are possible. 4) Employ Web Application Firewalls (WAFs) with rules targeting common XSS attack patterns to block malicious payloads. 5) Enable Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts on affected pages. 6) Monitor web server and application logs for unusual requests or script injection attempts. 7) Educate site administrators and users about the risks of XSS and encourage vigilance against suspicious site behavior. 8) Stay informed on updates from the plugin vendor and apply patches promptly once available. 9) Consider isolating critical user sessions and enforcing multi-factor authentication to reduce the impact of potential session hijacking. These steps go beyond generic advice by focusing on immediate plugin management, layered defenses, and proactive monitoring.