CVE-2024-0698 in Easy Appointments Plugin
Summary
by MITRE • 03/05/2024
The Easy!Appointments plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'easyappointments' shortcode in all versions up to, and including, 1.3.1 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions 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 • 04/12/2026
The vulnerability identified as CVE-2024-0698 affects the Easy!Appointments WordPress plugin, specifically targeting versions up to and including 1.3.1. This represents a critical security flaw that undermines the integrity of web applications by enabling malicious actors to inject persistent malicious code into the plugin's shortcode functionality. The vulnerability manifests through the 'easyappointments' shortcode which fails to properly validate or sanitize user-provided input parameters, creating an avenue for attackers to execute malicious scripts within the context of the affected website.
The technical flaw stems from inadequate input sanitization and output escaping mechanisms within the plugin's shortcode implementation. When administrators or users with contributor-level permissions and above utilize the shortcode functionality, they inadvertently expose the system to persistent cross-site scripting attacks. The vulnerability occurs because the plugin does not properly escape or validate attributes passed through the shortcode, allowing attackers to inject malicious JavaScript code that gets stored within the application's database or configuration files. This stored malicious content persists until manually removed, making it particularly dangerous as it can affect multiple users over extended periods.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the ability to manipulate user sessions, steal sensitive information, and potentially escalate privileges within the WordPress environment. Attackers can craft malicious shortcodes that, when processed by the vulnerable plugin, execute scripts in the context of authenticated users' browsers. This capability allows for session hijacking, data exfiltration, and the potential compromise of the entire WordPress installation. The vulnerability affects all users with contributor-level permissions and above, which typically includes content editors, authors, and administrators who have the ability to modify posts and pages containing the affected shortcode.
From a cybersecurity perspective, this vulnerability aligns with CWE-79 which identifies Cross-Site Scripting as a fundamental web application security flaw, and maps to ATT&CK technique T1566.001 for initial access through spearphishing attachments or links. The vulnerability exploitation process involves the attacker crafting malicious shortcode parameters that bypass input validation, storing these parameters within the WordPress database, and then waiting for users with appropriate permissions to access pages containing the malicious content. The persistent nature of the stored XSS makes this vulnerability particularly effective for long-term attacks and allows for the establishment of backdoors or data collection mechanisms that can operate without immediate detection.
Organizations should immediately implement several mitigation strategies to address this vulnerability. The most critical action is to upgrade to the latest version of the Easy!Appointments plugin where the vulnerability has been patched through proper input sanitization and output escaping mechanisms. Additionally, administrators should consider implementing strict content validation policies, limiting contributor-level permissions to only essential users, and monitoring for unauthorized shortcode modifications. Network-based solutions such as web application firewalls can provide additional protection layers, while regular security audits should verify that no malicious code has been injected into existing installations. The remediation process should also include comprehensive user education to prevent social engineering attacks that might exploit this vulnerability through malicious shortcode injection attempts.