CVE-2025-1410 in Events Calendar Made Simple Plugin
Summary
by MITRE • 02/21/2025
The Events Calendar Made Simple – Pie Calendar plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's piecal shortcode in all versions up to, and including, 1.2.5 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 02/25/2025
The CVE-2025-1410 vulnerability affects the Events Calendar Made Simple - Pie Calendar plugin for WordPress, a widely used calendar management solution that allows users to display event information through shortcode functionality. This particular vulnerability represents a critical security flaw that undermines the integrity of WordPress sites utilizing this plugin, potentially exposing thousands of websites to persistent cross-site scripting attacks. The vulnerability specifically targets the piecal shortcode implementation within the plugin's codebase, making it a prime target for attackers seeking to compromise WordPress installations that depend on this calendar functionality.
The technical flaw stems from inadequate input sanitization and output escaping mechanisms within the plugin's shortcode processing logic. When administrators or contributors with appropriate privileges create or modify calendar events through the plugin's interface, the system fails to properly validate or escape user-supplied attributes that are then processed through the piecal shortcode. This insufficient sanitization creates a persistent XSS vector where malicious scripts can be stored within the plugin's data structures and executed whenever the affected pages are rendered. The vulnerability affects all versions up to and including 1.2.5, indicating that the developers failed to implement proper security controls during the plugin's development lifecycle, leaving users exposed to attacks that could have been easily prevented through standard input validation practices.
The operational impact of this vulnerability is significant for WordPress administrators and site owners who rely on the Events Calendar Made Simple plugin for their website's event management capabilities. Attackers with contributor-level access or higher can inject malicious scripts that execute in the context of any user who views pages containing the compromised calendar data. This creates a persistent threat vector where malicious actors can establish backdoors, steal session cookies, perform account takeovers, or redirect users to phishing sites. The vulnerability's exploitation requires minimal privileges, making it particularly dangerous as it can be leveraged by users who normally have limited administrative capabilities. The stored nature of the XSS means that once an attacker successfully injects malicious code, it will continue to execute for all users who access the affected calendar pages until the vulnerability is patched or the malicious content is removed.
Organizations and individuals using this plugin should immediately implement mitigation strategies to protect their WordPress installations from potential exploitation. The primary recommendation involves updating to the latest version of the Events Calendar Made Simple - Pie Calendar plugin where the vulnerability has been addressed through proper input sanitization and output escaping mechanisms. Additionally, administrators should consider implementing additional security measures such as role-based access controls to limit the number of users with contributor privileges, regular security audits of plugin installations, and monitoring for suspicious activity within calendar-related content. From a compliance perspective, this vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and could potentially be leveraged as part of broader attack chains documented in the MITRE ATT&CK framework under techniques related to credential access and persistence. The vulnerability demonstrates the critical importance of input validation and output escaping in web applications, particularly in content management systems where user-generated content is frequently processed and displayed to other users.