CVE-2023-0167 in GetResponse for Plugin
Summary
by MITRE • 03/20/2023
The GetResponse for WordPress plugin through 5.5.31 does not validate and escape some of its shortcode attributes before outputting them back in a page/post where the shortcode is embed, which could allow users with the contributor role and above to perform Stored Cross-Site Scripting attacks.
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Analysis
by VulDB Data Team • 04/12/2023
The vulnerability identified as CVE-2023-0167 affects the GetResponse for WordPress plugin version 5.5.31 and earlier, presenting a significant security risk through stored cross-site scripting attacks. This issue specifically targets the plugin's handling of shortcode attributes within WordPress environments, where the vulnerability manifests due to insufficient input validation and output escaping mechanisms. The flaw allows malicious actors with contributor-level privileges or higher to inject malicious scripts into pages or posts containing the affected shortcodes, making it particularly concerning for WordPress sites with multiple user roles and collaborative editing environments.
The technical implementation of this vulnerability stems from the plugin's failure to properly sanitize and escape shortcode attributes before rendering them in the HTML output. When administrators or contributors embed GetResponse shortcodes within WordPress posts or pages, the plugin processes these shortcodes without adequate validation of user-supplied input. This lack of proper input sanitization creates an environment where malicious payloads can be stored within the WordPress database and subsequently executed whenever the affected page is rendered. The vulnerability specifically impacts the plugin's shortcode processing functionality, which is commonly used for embedding email marketing forms and tracking codes within WordPress content.
The operational impact of CVE-2023-0167 extends beyond simple script execution, as it provides attackers with the capability to manipulate user sessions, steal sensitive information, and potentially gain further access to the WordPress installation. Stored XSS attacks enabled by this vulnerability can persist for extended periods, as the malicious scripts remain embedded in the database until manually removed. This makes the vulnerability particularly dangerous for sites with high user activity or those that frequently update content, as the attack surface remains active and undetected for potentially months. The vulnerability affects WordPress sites that utilize the GetResponse plugin for marketing automation, customer engagement, and email campaign management, which are critical components of many business operations.
Security practitioners should consider this vulnerability in the context of CWE-79, which specifically addresses cross-site scripting flaws in software applications. The issue also aligns with ATT&CK technique T1566.001, which covers the use of malicious content to gain initial access or persistence within target environments. Organizations should prioritize immediate patching of the GetResponse plugin to version 5.5.32 or later, as this update addresses the insufficient input validation and output escaping mechanisms. Additionally, administrators should implement proper input validation at multiple layers, including WordPress plugin-level sanitization, content filtering, and regular security audits of embedded third-party scripts. The vulnerability demonstrates the importance of proper security practices in WordPress plugin development, particularly concerning user input handling and output encoding, which are fundamental requirements for preventing XSS attacks according to industry security standards and best practices.