CVE-2024-8701 in events-calendar Plugin
Summary
by MITRE • 05/16/2025
The events-calendar WordPress plugin through 1.0.4 does not sanitise and escape some of its settings, which could allow high privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup).
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Analysis
by VulDB Data Team • 06/13/2025
The CVE-2024-8701 vulnerability affects the events-calendar WordPress plugin version 1.0.4 and earlier, representing a critical stored cross-site scripting flaw that undermines web application security. This vulnerability specifically targets the plugin's handling of user settings, where insufficient sanitization and escaping of input data creates persistent XSS attack vectors. The flaw is particularly concerning because it affects high-privilege users including administrators who typically possess elevated capabilities within WordPress environments. The vulnerability exists despite the presence of security measures such as the unfiltered_html capability restriction, which is commonly employed in multisite configurations to prevent unrestricted HTML injection. This indicates that the plugin's security mechanisms fail to properly validate or sanitize data even when standard WordPress security controls are in place, creating a dangerous scenario where privileged users can bypass expected protections.
The technical implementation of this vulnerability stems from the plugin's failure to properly sanitize user-supplied input within its settings management system. When administrators or other high-privileged users configure plugin settings, the data is not adequately filtered or escaped before being stored and subsequently rendered in web pages. This creates a persistent XSS condition where malicious scripts can be stored in the plugin's configuration and executed whenever the affected settings are displayed or processed. The vulnerability operates under CWE-79 which categorizes cross-site scripting flaws as weaknesses in input validation and output encoding. The attack vector is particularly dangerous because it leverages the elevated privileges of administrative users to inject malicious payloads that can persist across sessions and affect multiple users who interact with the plugin's interface. The stored nature of this XSS means that the malicious code remains embedded in the system and executes automatically whenever the affected page is loaded, rather than requiring a specific user interaction to trigger.
The operational impact of CVE-2024-8701 extends beyond simple script execution, as it provides attackers with potential access to administrative functions and sensitive data within WordPress environments. In multisite configurations where the unfiltered_html capability is restricted, this vulnerability creates a significant bypass mechanism that undermines the security model of WordPress multisite installations. Attackers can leverage this vulnerability to execute malicious scripts that may harvest user credentials, manipulate plugin functionality, or redirect users to malicious sites. The persistent nature of stored XSS allows for long-term exploitation without requiring repeated user interaction, making it particularly dangerous in environments where administrators frequently access plugin settings. This vulnerability aligns with ATT&CK technique T1566.001 which covers spearphishing attachments, as the malicious scripts could be used to establish initial access or maintain persistence within compromised WordPress installations. The security implications are amplified in enterprise environments where WordPress multisite setups are common and administrative privileges are concentrated.
Mitigation strategies for CVE-2024-8701 should focus on immediate remediation through plugin updates to versions that properly sanitize and escape user input. Organizations should implement strict input validation mechanisms at both the application and database levels to prevent malicious data from being stored in plugin settings. Security teams should also consider implementing Content Security Policy (CSP) headers to add additional layers of protection against XSS attacks, though this should not replace proper input sanitization. Regular security audits of WordPress plugins should include verification of sanitization practices and output escaping mechanisms to prevent similar vulnerabilities from being introduced. Additionally, privileged user accounts should be monitored for unusual activity patterns that might indicate exploitation attempts, and multi-factor authentication should be implemented for administrative accounts to reduce the impact of successful XSS exploitation. The vulnerability underscores the importance of following secure coding practices as outlined in OWASP Top Ten and other industry standards, particularly regarding input validation and output encoding in web applications. Organizations should also maintain updated vulnerability management processes that include monitoring for plugin-specific security advisories and ensuring timely patch deployment across all WordPress installations.