CVE-2024-11804 in API Plugin
Summary
by MITRE • 12/12/2024
The Planaday API plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'tab' parameter in all versions up to, and including, 11.4 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.
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Analysis
by VulDB Data Team • 02/18/2025
The vulnerability identified as CVE-2024-11804 affects the Planaday API plugin for WordPress, a widely used tool for managing scheduling and appointment booking functionalities within WordPress environments. This particular flaw represents a critical security weakness that has been present in all versions up to and including 11.4, exposing countless WordPress installations to potential exploitation by malicious actors. The vulnerability specifically resides in how the plugin handles the 'tab' parameter within its API endpoints, creating an avenue for attackers to execute malicious code through crafted web requests.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization practices within the plugin's codebase. When the 'tab' parameter is processed by the Planaday API plugin, it fails to properly sanitize user-supplied input before incorporating it into web responses. This insufficient sanitization combined with inadequate output escaping creates a classic reflected cross-site scripting scenario where malicious payloads can be injected and executed in the context of a victim's browser session. The vulnerability operates under CWE-79 which specifically addresses Cross-Site Scripting flaws, and aligns with ATT&CK technique T1531 which focuses on establishing persistence through web shell or script injection methods. The reflected nature of this XSS means that the malicious script must be delivered through an external source to a victim, typically via a malicious link or email attachment.
The operational impact of this vulnerability extends beyond simple data theft or session hijacking, as it provides attackers with the capability to perform a wide range of malicious activities within the context of authenticated user sessions. An unauthenticated attacker can craft malicious URLs containing script payloads that, when clicked by an unsuspecting user, will execute the injected code in the victim's browser. This could potentially lead to unauthorized access to sensitive scheduling data, modification of booking information, or even the complete compromise of user accounts if the victim is an administrator. The vulnerability is particularly concerning because it affects a plugin that likely handles sensitive personal and business scheduling information, making it attractive to cybercriminals seeking to exploit user trust and access privileges.
Mitigation strategies for this vulnerability should begin with immediate plugin updates to versions that have addressed the XSS flaw, as the vendor has likely released patches containing proper input sanitization and output escaping mechanisms. System administrators should also implement additional defensive measures including web application firewalls that can detect and block malicious payloads targeting this specific parameter, and regular security monitoring to identify potential exploitation attempts. Network-level protections such as content security policies can provide additional layers of defense by restricting script execution from untrusted sources, while user education programs should emphasize the importance of verifying links and avoiding suspicious email attachments. Organizations should also conduct thorough vulnerability assessments to ensure no other plugins or components within their WordPress environment contain similar input validation weaknesses, as this vulnerability represents a pattern of insecure coding practices that may exist elsewhere in the application stack.