CVE-2013-2107 in Mail On Update
Summary
by MITRE
Cross-site request forgery (CSRF) vulnerability in the Mail On Update plugin before 5.2.0 for WordPress allows remote attackers to hijack the authentication of administrators for requests that change the "List of alternative recipients" via the mailonupdate_mailto parameter in the mail-on-update page to wp-admin/options-general.php. NOTE: a third party claims that 5.2.1 and 5.2.2 are also vulnerable, but the issue might require a separate CVE identifier since this might reflect an incomplete fix.
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Analysis
by VulDB Data Team • 03/10/2025
The CVE-2013-2107 vulnerability represents a critical cross-site request forgery flaw in the Mail On Update WordPress plugin affecting versions prior to 5.2.0. This vulnerability specifically targets the administrative interface of WordPress installations, creating a significant security risk for users who employ this plugin. The flaw allows remote attackers to exploit the lack of proper authentication verification mechanisms, enabling them to manipulate administrative settings without legitimate authorization. The vulnerability manifests through the mailonupdate_mailto parameter within the mail-on-update page that leads to wp-admin/options-general.php, making it particularly dangerous as it directly targets the core WordPress administration area where critical configuration changes can be made.
The technical implementation of this CSRF vulnerability stems from the absence of proper anti-forgery tokens or nonce validation within the Mail On Update plugin's administrative forms. When administrators visit the mail-on-update page, the plugin fails to verify that requests originated from legitimate administrative sessions rather than maliciously crafted cross-site requests. Attackers can construct malicious web pages or exploit existing vulnerabilities in other parts of the website to automatically submit requests that modify the "List of alternative recipients" configuration. This particular parameter manipulation allows attackers to redirect email notifications to addresses they control, potentially leading to unauthorized access to sensitive information, data exfiltration, or further exploitation of the compromised WordPress installation. The vulnerability aligns with CWE-352, which specifically addresses Cross-Site Request Forgery issues in web applications, and represents a classic example of how insufficient input validation and authentication checks can create exploitable conditions in web-based administrative interfaces.
The operational impact of this vulnerability extends beyond simple email redirection, as it provides attackers with a foothold for more extensive compromise of WordPress installations. When administrators with elevated privileges access malicious pages, their sessions become vulnerable to hijacking, potentially allowing attackers to make additional configuration changes or escalate privileges further. The attack vector requires minimal user interaction beyond visiting a malicious page, making it particularly effective for social engineering campaigns or when attackers have already gained some level of access to the target environment. The fact that versions 5.2.1 and 5.2.2 are reportedly also vulnerable suggests that the initial patch may have been incomplete or improperly implemented, leaving administrators who upgraded to these versions still exposed to the same attack surface. This incomplete remediation demonstrates the importance of thorough testing and validation of security patches, as well as the potential for attackers to identify and exploit vulnerabilities in the patching process itself.
Organizations affected by this vulnerability should implement immediate mitigations including updating to version 5.2.0 or later of the Mail On Update plugin, applying the proper security patches, and verifying that the fix correctly implements CSRF protection mechanisms. Network administrators should also monitor for suspicious administrative activities and implement additional security controls such as role-based access restrictions, multi-factor authentication for administrative accounts, and regular security audits of installed plugins. The vulnerability highlights the necessity of maintaining up-to-date security practices and demonstrates how even seemingly minor configuration parameters can create significant security risks when proper validation mechanisms are absent. From an ATT&CK framework perspective, this vulnerability maps to T1078 (Valid Accounts) and T1548.002 (Abuse Elevation Control Mechanism) as attackers can leverage compromised administrative sessions to perform unauthorized actions, while also representing a technique for T1213 (Data from Information Repositories) through potential email redirection to capture sensitive communications. Organizations should also consider implementing Content Security Policy headers and additional web application firewall rules to provide defense-in-depth against similar CSRF attacks targeting WordPress installations and other web applications.